Entry - #600791 - DEAFNESS, AUTOSOMAL RECESSIVE 4, WITH ENLARGED VESTIBULAR AQUEDUCT; DFNB4 - OMIM

# 600791

DEAFNESS, AUTOSOMAL RECESSIVE 4, WITH ENLARGED VESTIBULAR AQUEDUCT; DFNB4


Alternative titles; symbols

NEUROSENSORY NONSYNDROMIC RECESSIVE DEAFNESS 4; NSRD4
DILATED VESTIBULAR AQUEDUCT; DVA


Phenotype-Gene Relationships

Location Phenotype Phenotype
MIM number
Inheritance Phenotype
mapping key
Gene/Locus Gene/Locus
MIM number
1q23.2 Enlarged vestibular aqueduct, digenic 600791 AR 3 KCNJ10 602208
5q35.1 Enlarged vestibular aqueduct 600791 AR 3 FOXI1 601093
7q22.3 Deafness, autosomal recessive 4, with enlarged vestibular aqueduct 600791 AR 3 SLC26A4 605646
Clinical Synopsis
 
Phenotypic Series
 

INHERITANCE
- Autosomal recessive
HEAD & NECK
Ears
- Hearing loss, sensorineural
- Vestibular abnormalities (variable)
- Enlarged vestibular aqueduct
- Cochlear malformation defect (Mondini dysplasia) (less common)
MISCELLANEOUS
- Hearing loss is pre- or perilingual in onset
- Hearing loss may be fluctuating or progressive
- Allelic to Pendred syndrome, deafness with goiter (274600)
MOLECULAR BASIS
- Caused by mutation in the solute carrier family 26, member 4 gene (SLC26A4, 605646.0004)
Deafness, autosomal recessive - PS220290 - 108 Entries
Location Phenotype Inheritance Phenotype
mapping key
Phenotype
MIM number
Gene/Locus Gene/Locus
MIM number
1p36.31-p36.13 Deafness, autosomal recessive 96 AR 2 614414 DFNB96 614414
1p36.31 Deafness, autosomal recessive 36 AR 3 609006 ESPN 606351
1p36.31 Deafness, neurosensory, without vestibular involvement, autosomal dominant AR 3 609006 ESPN 606351
1p34.3 Deafness, digenic, GJB2/GJB3 AR, DD 3 220290 GJB3 603324
1p31.3 ?Deafness, autosomal recessive 108 AR 3 617654 ROR1 602336
1p21.2 Deafness, autosomal recessive 32, with or without immotile sperm AR 3 608653 CDC14A 603504
1q23.2 Enlarged vestibular aqueduct, digenic AR 3 600791 KCNJ10 602208
1q43-q44 Deafness, autosomal recessive 45 AR 2 612433 DFNB45 612433
2p25.1-p24.3 Deafness, neurosensory, autosomal recessive 47 AR 2 609946 DFNB47 609946
2p23.3 Deafness, autosomal recessive 9 AR 3 601071 OTOF 603681
2p23.3 Auditory neuropathy, autosomal recessive, 1 AR 3 601071 OTOF 603681
2p16.1 Deafness, autosomal recessive 70, with or without adult-onset neurodegeneration AR 3 614934 PNPT1 610316
2p11.2 ?Deafness, autosomal recessive 88 AR 3 615429 ELMOD3 615427
2q23-q31 Deafness, autosomal recessive 27 AR 2 605818 DFNB27 605818
2q31.2 Deafness, autosomal recessive 59 AR 3 610220 PJVK 610219
3p25.3 {Deafness, autosomal recessive 12, modifier of} AR 3 601386 ATP2B2 108733
3p21.31 Deafness, autosomal recessive 6 AR 3 600971 TMIE 607237
3q13.33 Deafness, autosomal recessive 121 AR 3 620551 GPR156 610464
3q13.33 Deafness, autosomal recessive 42 AR 3 609646 ILDR1 609739
4p15.32 Deafness, autosomal recessive 117 AR 3 619174 CLRN2 618988
4p13 Deafness, autosomal recessive 25 AR 3 613285 GRXCR1 613283
4q12-q13.2 Deafness, autosomal recessive 55 AR 2 609952 DFNB55 609952
4q31.21 ?Deafness, autosomal recessive 26 AR 3 605428 GAB1 604439
5q13.2 Deafness, autosomal recessive 49 AR 3 610153 MARVELD2 610572
5q13.2 ?Deafness, autosomal recessive 112 AR 3 618257 BDP1 607012
5q21.1 Deafness, autosomal recessive 100 AR 3 618422 PPIP5K2 611648
5q23.3 Deafness, autosomal recessive 120 AR 3 620238 MINAR2 620215
5q32 ?Deafness, autosomal recessive 101 AR 3 615837 GRXCR2 615762
5q35.1 Enlarged vestibular aqueduct AR 3 600791 FOXI1 601093
6p25.2 ?Deafness, autosomal recessive 91 AR 3 613453 SERPINB6 173321
6p22.3 ?Deafness, autosomal recessive 66 AR 3 610212 DCDC2 605755
6p22.3 ?Deafness, autosomal recessive 104 AR 3 616515 RIPOR2 611410
6p21.32 Deafness, autosomal recessive 53 AR 3 609706 COL11A2 120290
6p21.31 Deafness, autosomal recessive 67 AR 3 610265 LHFPL5 609427
6p21.1 ?Deafness, autosomal recessive 103 AR 3 616042 CLIC5 607293
6q14.1 Deafness, autosomal recessive 37 AR 3 607821 MYO6 600970
6q26-q27 Deafness, autosomal recessive 38 AR 2 608219 DFNB38 608219
7p12.3 ?Deafness, autosomal recessive 44 AR 3 610154 ADCY1 103072
7q21.11 Deafness, autosomal recessive 39 AR 3 608265 HGF 142409
7q22.1 ?Deafness, autosomal recessive 61 AR 3 613865 SLC26A5 604943
7q22.3 Deafness, autosomal recessive 4, with enlarged vestibular aqueduct AR 3 600791 SLC26A4 605646
7q31 Deafness, autosomal recessive 14 AR 2 603678 DFNB14 603678
7q31 Deafness, autosomal recessive 17 AR 2 603010 DFNB17 603010
7q31.2 ?Deafness, autosomal recessive 97 AR 3 616705 MET 164860
7q34-q36 Deafness, autosomal recessive 13 AR 2 603098 DFNB13 603098
8p22-p21.3 Deafness, autosomal recessive 71 AR 2 612789 DFNB71 612789
8q22 Deafness, autosomal recessive 118, with cochlear aplasia AR 4 619553 DFNB118 619553
8q22.1 ?Deafness, autosomal recessive 109 AR 3 618013 ESRP1 612959
8q23.1-q23.2 Deafness, autosomal recessive 124 3 620794 PKHD1L1 607843
9p23-p21.2 Deafness, autosomal recessive 83 AR 2 613685 DFNB83 613685
9q21.13 Deafness, autosomal recessive 7 AR 3 600974 TMC1 606706
9q32 Deafness, autosomal recessive 31 AR 3 607084 WHRN 607928
9q34.3 Deafness, autosomal recessive 79 AR 3 613307 TPRN 613354
10p12.1 Deafness, autosomal recessive 30 AR 3 607101 MYO3A 606808
10p11.23-q21.1 Deafness, autosomal recessive 33 AR 2 607239 DFNB33 607239
10q21.1 Deafness, autosomal recessive 23 AR 3 609533 PCDH15 605514
10q22.1 Deafness, autosomal recessive 12 AR 3 601386 CDH23 605516
10q24.31 Deafness, autosomal recessive 57 AR 3 618003 PDZD7 612971
11p15.5 Deafness autosomal recessive 106 AR 3 617637 EPS8L2 614988
11p15.1 Deafness, autosomal recessive 18A AR 3 602092 USH1C 605242
11p15.1 Deafness, autosomal recessive 18B AR 3 614945 OTOG 604487
11p13-p12 Deafness, autosomal recessive 51 AR 2 609941 DFNB51 609941
11q13.2 Deafness, autosomal recessive 93 AR 3 614899 CABP2 607314
11q13.4 Deafness, autosomal recessive 63 AR 3 611451 LRTOMT 612414
11q13.5 Deafness, autosomal recessive 2 AR 3 600060 MYO7A 276903
11q14.1 ?Deafness, autosomal recessive 94 AR 3 618434 NARS2 612803
11q22.3 Deafness, autosomal recessive 24 AR 3 611022 RDX 179410
11q23.3 Deafness, autosomal recessive 111 AR 3 618145 MPZL2 604873
11q23.3 Deafness, autosomal recessive 21 AR 3 603629 TECTA 602574
11q25-qter Deafness, autosomal recessive 20 AR 2 604060 DFNB20 604060
12p13.2-p11.23 Deafness, autosomal recessive 62 AR 2 610143 DFNB62 610143
12p12.3 ?Deafness, autosomal recessive 102 AR 3 615974 EPS8 600206
12q14.3 Deafness, autosomal recessive 74 AR 3 613718 MSRB3 613719
12q21.31 Deafness, autosomal recessive 84B AR 3 614944 OTOGL 614925
12q21.31 Deafness, autosomal recessive 84A AR 3 613391 PTPRQ 603317
13q12.11 Deafness, autosomal recessive 1A AR, DD 3 220290 GJB2 121011
13q12.11 Deafness, digenic GJB2/GJB6 AR, DD 3 220290 GJB6 604418
13q12.11 Deafness, autosomal recessive 1B AR 3 612645 GJB6 604418
13q32.3 ?Deafness, autosomal recessive 122 AR 3 620714 TMTC4 618203
14q12 Deafness, autosomal recessive 5 AR 2 600792 DFNB5 600792
14q12 ?Deafness, autosomal recessive 110 AR 3 618094 COCH 603196
14q24.3 Deafness, autosomal recessive 35 AR 3 608565 ESRRB 602167
15q15.3 Deafness, autosomal recessive 16 AR 3 603720 STRC 606440
15q21.1 Deafness, autosomal recessive 119 AR 3 619615 AFG2B 619578
15q25.1 Deafness, autosomal recessive 48 AR 3 609439 CIB2 605564
16p13.3 Deafness, autosomal recessive 86 AR 3 614617 TBC1D24 613577
16p13.3 ?Deafness, autosomal recessive 116 AR 3 619093 CLDN9 615799
16p12.2 Deafness, autosomal recessive 22 AR 3 607039 OTOA 607038
16p11.2 ?Deafness, autosomal recessive 123 AR 3 620745 STX4 186591
16q23.1 Deafness, autosomal recessive 89 AR 3 613916 KARS1 601421
17p13.2 ?Deafness, autosomal recessive 115 AR 3 618457 SPNS2 612584
17p12-q11.2 Deafness, autosomal recessive 85 AR 2 613392 DFNB85 613392
17p11.2 Deafness, autosomal recessive 3 AR 3 600316 MYO15A 602666
17p11.2 Deafness, autosomal recessive 114 AR 3 618456 GRAP 604330
17q12 Deafness, autosomal recessive 99 AR 3 618481 TMEM132E 616178
17q25.1 Deafness, autosomal recessive 107 AR 3 617639 WBP2 606962
18p11.32-p11.31 Deafness, autosomal recessive 46 AR 2 609647 DFNB46 609647
18q21.1 Deafness, autosomal recessive 77 AR 3 613079 LOXHD1 613072
19p13.3 Deafness, autosomal recessive 15 AR 3 601869 GIPC3 608792
19p13.2 Deafness, autosomal recessive 68 AR 3 610419 S1PR2 605111
19q13.12 Deafness, autosomal recessive 76 AR 3 615540 SYNE4 615535
19q13.31-q13.32 Deafness, autosomal recessive 113 AR 3 618410 CEACAM16 614591
20q13.2-q13.3 Deafness, autosomal recessive 65 AR 2 610248 DFNB65 610248
21q22.13 Deafness, autosomal recessive 29 AR 3 614035 CLDN14 605608
21q22.3 Deafness, autosomal recessive 8/10 AR 3 601072 TMPRSS3 605511
21q22.3 ?Deafness, autosomal recessive 98 AR 3 614861 TSPEAR 612920
22q11.21-q12.1 Deafness, autosomal recessive 40 AR 2 608264 DFNB40 608264
22q13.1 Deafness, autosomal recessive 28 AR 3 609823 TRIOBP 609761

TEXT

A number sign (#) is used with this entry because of evidence that autosomal recessive deafness-4 (DFNB4) with enlarged vestibular aqueduct (EVA) is caused by homozygous or compound heterozygous mutation in the SLC26A4 gene (605646) on chromosome 7q22.

Mutation in the FOXI1 gene (601093) has been found to be a rare cause of EVA. EVA may also be rarely caused by digenic inheritance of heterozygous mutations in the SLC26A4 and FOXI1 genes, or in the SLC26A4 and KCNJ10 (602208) genes.

Mutations in the SLC26A4 gene also cause Pendred syndrome (PDS; 274600), a disorder comprising congenital sensorineural hearing loss, cochlear abnormalities (EVA or Mondini dysplasia), and thyroid enlargement (goiter).


Description

DFNB4 with enlarged vestibular aqueduct is characterized by pre- or perilingual onset of sensorineural or mixed hearing loss, which may be fluctuating or progressive. The hearing loss is associated with temporal bone abnormalities, most commonly enlargement of the vestibular aqueduct, but it can also include the more severe Mondini dysplasia, a complex malformation in which the normal cochlear spiral of 2.5 turns is replaced by a hypoplastic coil of 1.5 turns (summary by Campbell et al., 2001 and Pryor et al., 2005). Enlarged vestibular aqueduct is the most common form of inner ear abnormality and can be associated with disequilibrium symptoms in a minority of patients (Valvassori, 1983; Jackler and de la Cruz, 1989; Levenson et al., 1989; Arcand et al., 1991; Belenky et al., 1993; Okumura et al., 1995).


Clinical Features

Griffith et al. (1996) reported a family in which 2 brothers had sensorineural hearing loss and enlarged vestibular aqueduct with no other abnormalities. Their parents were unaffected. The authors suggested autosomal recessive or X-linked inheritance with variable expressivity of the disorder in this family.

Abe et al. (1997) reported 3 families in which 2 sibs in each had congenital, high-frequency, fluctuating sensorineural hearing loss associated with enlargement of the vestibular aqueduct. Both parents in all 3 families were unaffected, suggesting autosomal recessive inheritance of the disorder.

Abe et al. (1999) studied 13 patients from 9 Japanese families and 2 patients from a Caucasian family who had congenital high frequency-dominant fluctuating sensorineural hearing loss and EVA on CT scan. Gadolidium-enhanced MRI confirmed the enlarged endolymphatic duct and sac. Hearing loss in some patient was progressive but with fluctuations, and about one-third had a history of vertigo. The perchlorate discharge test was performed in 8 patients from 6 of the families; all results were normal. Three of these families had been described previously by Abe et al. (1997).

Li et al. (1998) studied a large consanguineous family from southwest India in which 10 individuals ranging in age from 5 to 38 years were affected with congenital, profound, nonsyndromic autosomal recessive deafness. No goiter was palpable in any of the affected individuals and, although the perchlorate discharge test was not available, several other tests of thyroid function were normal. Axial and coronal computerized tomography of the temporal bone showed bilateral large vestibular aqueducts in all 3 affected individuals who were studied, with no Mondini-type cochlear malformation.


Mapping

Baldwin et al. (1995) described a large Middle-Eastern Druze family with recessive nonsyndromic deafness and demonstrated linkage between deafness in this family and 7q31 with a lod score exceeding 5.5. Baldwin et al. (1995) designated the locus DFNB4. In addition, they found that deafness in 3 other Druze pedigrees, including 1 related to the linked family, was not linked to 7q31. Thus, there appear to be multiple nonallelic mutations for deafness in this genetic isolate. On the basis of a personal communication from Baldwin (1998), Li et al. (1998) purported that the Israeli-Druze family indeed had Pendred syndrome. Affected members of this family were later found to have goiters.

Everett et al. (1997) identified SLC26A4 (605646) as the gene mutant in Pendred syndrome (PDS; 274600) in 3 families. The gene maps to 7q31. They pointed out that DFNB4 also maps to 7q31 and considered it likely that the DFNB4 individuals reported actually have PDS, rather than mutations in another gene.

By linkage analysis in 9 Japanese families and 1 Caucasian family with sensorineural hearing loss associated with EVA, Abe et al. (1999) localized the gene responsible to 7q31, with a maximum multipoint lod score of 3.647. The EVA candidate gene region was found to lie in a 1.7-cM interval between flanking markers D7S501 and D7S2425. Although this region overlaps the region containing the gene responsible for Pendred syndrome, these patients did not fulfill the criteria for PDS.


Molecular Genetics

Mutations in the SLC26A4 Gene

In affected members of a large consanguineous family from southwest India with DFNB4 with EVA, Li et al. (1998) found linkage to chromosome 7q31 and demonstrated that affected individuals were compound homozygotes for 2 mutations in exon 13 of the PDS gene (605646.0004).

Usami et al. (1999) screened the SLC26A4 gene for mutations in 6 families with congenital nonsyndromic high frequency, fluctuating, sometimes progressive sensorineural hearing loss, and enlarged vestibular aqueduct diagnosed by CT. One patient had a history of vertigo; none had Mondini malformation. Affected individuals in 4 of the 6 families were homozygous or compound heterozygous for SLC26A4 mutations (605646.0009-605646.0015).

Campbell et al. (2001) found mutations in the SLC26A4 gene in 5 of 6 multiplex families with EVA (83%) and in 4 of 5 multiplex families with Mondini dysplasia (80%), implying that mutations in the SLC26A4 gene are the major genetic cause of these temporal abnormalities. In their analyses of Pendred syndrome and DFNB4, they found that the 2 most common mutations, T416P (605646.0006) and IVS8+1G-A (605646.0007), were present in 22% and 30% of families, respectively.

Recessive mutations in the anion transporter gene SLC26A4 are known to be responsible for Pendred syndrome and for nonsyndromic hearing loss associated with EVA. However, a large percentage of patients with these phenotypes lack mutations in the SLC26A4 coding region in one or both alleles. Yang et al. (2007) identified and characterized a key transcriptional regulatory element in the SLC26A4 promoter that binds FOXI1 (601093), which is a transcriptional activator of SLC26A4. They found 9 patients with Pendred syndrome or nonsyndromic EVA who were heterozygous for a novel -103T-C mutation (605646.0027) in this regulatory element of the SLC26A4 gene that interfered with FOXI1 binding and completely abolished FOXI1-mediated transcriptional activation.

Mutation in the FOXI1 Gene

In 2 families given a diagnosis of enlarged vestibular aqueduct, Yang et al. (2007) found heterozygosity for a mutation in the FOXI1 gene (601093.0002). Although both of these families were classified by the authors as 'nonsyndromic EVA,' in one of them goiter reminiscent of Pendred syndrome was noted. Both alleles of the SLC26A4 gene were wildtype. The FOXI1 mutation showed significantly decreased luciferase activation in promoter-reporter assays, suggesting that this variant compromised the ability of FOXI1 to transactivate SLC26A4 and was causally related to disease.

Digenic Inheritance

Yang et al. (2007) reported a patient with DFNB4 and EVA who was compound heterozygous for a mutation in 2 different genes. The patient had a heterozygous mutation in the SLC26A4 gene (605646.0028) and a heterozygous mutation in the FOXI1 gene (601093.0001). This finding was consistent with their observation that EVA occurs in the mouse mutant doubly heterozygous for mutations in these 2 genes, and the results supported a dosage-dependent model for the molecular pathogenesis of nonsyndromic EVA that involves SLC26A4 and its transcriptional regulatory machinery. Yang et al. (2007) stated the this was the first example of digenic inheritance to be verified as a cause of human deafness.

Yang et al. (2009) sequenced the KCNJ10 gene (602208) in 89 patients who had a clinical diagnosis of EVA/Pendred syndrome and were known to carry only 1 SLC26A4 coding sequence mutation; promoter mutations and deletions of SLC26A4 were excluded in this patient cohort. In 2 patients, Yang et al. (2009) identified missense mutations in KCNJ10 (P194H, 602208.0008 and R348C, 602208.0009, respectively). The former patient carried a F335L mutation in SLC26A4 (605646.0031), and the latter a splice site mutation (605646.0029). Both KCNJ10 mutations reduce potassium conductance activity, which is critical for generating and maintaining the endocochlear potential.


Genotype/Phenotype Correlations

Scott et al. (2000) compared 3 common Pendred syndrome allele variants with 3 PDS mutations reported only in individuals with nonsyndromic hearing loss. The mutations associated with Pendred syndrome exhibited complete loss of pendrin (SLC26A4)-induced chloride and iodide transport, while alleles unique to patients with DFNB4 were able to transport both iodide and chloride, albeit at a much lower level than wildtype pendrin. The authors hypothesized that the residual level of anion transport was sufficient to eliminate or postpone the onset of goiter in individuals with DFNB4. They proposed a model for pendrin function in the thyroid in which pendrin transports iodide across the apical membrane of the thyrocyte into the colloid space.

Tsukamoto et al. (2003) screened 10 Japanese families with Pendred syndrome, 32 Japanese families with bilateral sensorineural hearing loss associated with EVA, and 96 unrelated Japanese controls for mutations in the SLC26A4 gene. They identified causative mutations in 90% of the typical Pendred syndrome families and in 78.1% of those with sensorineural hearing loss with EVA. None of their patients had the Mondini malformation. Tsukamoto et al. (2003) noted that the same combination of mutations resulted in variable phenotypic expression (see, e.g., 605646.0011 and 605646.0012), suggesting that these 2 conditions are part of a continuous spectrum of disease.

Pryor et al. (2005) evaluated the clinical phenotype and SLC26A4 genotype of 39 patients with EVA from 31 families, definitively classifying 29 individuals. All 11 PDS patients had 2 mutant SLC26A4 alleles, whereas all 18 nonsyndromic EVA patients had either 1 or no SLC26A4 mutant alleles. Pryor et al. (2005) concluded that PDS and nonsyndromic EVA are distinct clinical and genetic entities, with PDS being a genetically homogeneous disorder caused by biallelic SLC26A4 mutations, and at least some cases of nonsyndromic EVA being associated with a single SLC26A4 mutation. They noted that the detection of a single mutant SLC26A4 allele is incompletely diagnostic without additional clinical evaluation to differentiate PDS from nonsyndromic EVA.

Albert et al. (2006) analyzed the SLC26A4 gene in 109 patients from 100 unrelated French Caucasian families with nonsyndromic deafness and enlarged vestibular aqueduct and no mutation in the GJB2 gene (121011). They identified 91 allelic variants in 40 unrelated families (prevalence of SLC26A4 mutations, 40%). There were 18 compound heterozygous and 6 homozygous families; Albert et al. (2006) noted that patients with biallelic mutations had more severe deafness, an earlier age of diagnosis, and a more fluctuating course than patients in whom no mutation was identified. Albert et al. (2006) estimated that up to 4% of nonsyndromic hearing impairment could be caused by SLC26A4 mutations.

In 71 families with EVA, Choi et al. (2009) used sequence analysis of SLC26A4 coding and conserved noncoding regions and CGH microarray analysis, and compared segregation of EVA among families with 2, 1, or no detectable mutant alleles of SLC26A4. EVA segregation ratios were similar in families with 1 or 2 mutant alleles, but the segregation ratio for families with 1 mutation was significantly higher than that of families with no SLC26A4 mutations. Haplotype analyses revealed discordant segregation of EVA with SLC26A4-linked STR markers in 8 of 24 families with no mutation in SLC26A4. Choi et al. (2009) concluded that families with EVA and 1 detectable mutation in SLC26A4 were likely to be segregating EVA as a trait caused by that mutation in combination with a second occult mutant allele of SLC26A4 or of another autosomal gene. In contrast, EVA appeared to be a nongenetic or complex trait with a significantly lower recurrence rate in families with no detectable SLC26A4 mutation.

Chattaraj et al. (2017) performed genotype-haplotype analysis and massively parallel sequencing of the SLC26A4 gene in patients with EVA and only 1 detected mutant allele in the SLC26A4 gene. The authors identified a shared novel haplotype, termed CEVA (Caucasian EVA), composed of 12 uncommon variants upstream of SLC26A4. The presence of the CEVA haplotype on 7 of 10 mutation-negative chromosomes in a National Institutes of Health discovery cohort and 6 of 6 mutation-negative chromosomes in a Danish replication cohort was higher than the observed prevalence of 28 of 1,006 Caucasian control chromosomes (p less than 0.0001 for each EVA cohort). The corresponding heterozygous carrier rate was 28 of 503 (5.6%). The prevalence of CEVA (11 of 126) was also increased among EVA chromosomes with no mutations detected (p = 0.0042). Chattaraj et al. (2017) concluded that the CEVA haplotype causally contributes to most cases of Caucasian EVA, being present in cases where only 1 mutation is detected by traditional exonic sequencing, and possibly in some cases where no mutation has been detected.


Population Genetics

Wang et al. (2007) identified a total of 40 SLC26A4 mutations, including 25 novel mutations, among 107 Chinese patients with EVA from 101 families. Overall, SLC26A4 mutations were identified in 97.9% of patients. The most common mutation was a splice site transition (IVS7-2A-G; 605646.0029), which accounted for 57.6% of mutant alleles. Park et al. (2005) identified the same splice site mutation in 9 (20%) of 45 mutant alleles in a study of Korean EVA patients. In 15 patients from 13 unrelated Chinese families with deafness and EVA, Hu et al. (2007) identified the IVS7-2A-G mutation in 5 (22.3%) of 22 mutant alleles. Reviewing previously published studies involving Chinese patients, the authors stated that IVS7-2A-G accounted for 69.1% (76 of 110) of all mutant alleles in the Chinese, suggesting a founder effect.

Pourova et al. (2010) screened the SLC26A4 gene in 303 Czech patients with early-onset hearing loss. The patients were divided into 3 groups: 22 with EVA and/or Mondini malformation on imaging, 220 patients without imaging available, and 61 patients with EVA/Mondini-negative imaging studies. Biallelic SLC26A4 mutations were found in 6 (27.3%) patients in the first group, 2 (0.9%) patients in the second group, and none (0%) in the third group; 4 of the 8 patients with biallelic mutations had goiter, consistent with Pendred syndrome. Monoallelic SLC26A4 mutations were found in 3 (13.6%) patients in the first group, 12 (5.5%) patients in the second group, and 3 (4.9%) patients in the third group. The most frequent mutations were V138F (605646.0024) and L445W (605646.0018), in 18% and 8.9% alleles, respectively. Among 13 patients with bilateral EVA, 6 (46%) carried biallelic mutations. No biallelic mutations were found in EVA-negative patients, but 4.9% had monoallelic mutations. Overall, biallelic mutations were found in only 2.7% of all patients, but were more common in familial cases. The findings also suggested that a single SLC26A4 mutation may contribute to the phenotype, perhaps in concert with mutations in other genes.


Nomenclature

In the title of their paper, Baldwin et al. (1995) referred to the form of deafness that maps to 7q31 as DFNB4. The same symbol was used by Fukushima et al. (1995) for a locus on chromosome 14 (600792). The chromosome 14 locus is, in fact, symbolized DFNB5.


REFERENCES

  1. Abe, S., Usami, S., Hoover, D. M., Cohn, E., Shinkawa, H., Kimberling, W. J. Fluctuating sensorineural hearing loss associated with enlarged vestibular aqueduct maps to 7q31, the region containing the Pendred gene. Am. J. Med. Genet. 82: 322-328, 1999. [PubMed: 10051166, related citations]

  2. Abe, S., Usami, S., Shinkawa, H. Three familial cases of hearing loss associated with enlargement of the vestibular aqueduct. Ann. Otol. Rhinol. Laryng. 106: 1063-1069, 1997. [PubMed: 9415602, related citations] [Full Text]

  3. Albert, S., Blons, H., Jonard, L., Feldmann, D., Chauvin, P., Loundon, N., Sergent-Allaoui, A., Houang, M., Joannard, A., Schmerber, S., Delobel, B., Leman, J., and 18 others. SLC26A4 gene is frequently involved in nonsyndromic hearing impairment with enlarged vestibular aqueduct in Caucasian populations. Europ. J. Hum. Genet. 14: 773-779, 2006. [PubMed: 16570074, related citations] [Full Text]

  4. Arcand, P., Desrosiers, M., Dube, J., Abela, A. The large vestibular aqueduct syndrome and sensorineural hearing loss in the pediatric population. J. Otolaryng. 20: 247-250, 1991. [PubMed: 1920576, related citations]

  5. Baldwin, C. T., Weiss, S., Farrer, L., De Stefano, A., Adair, R., Franklyn, B., Kidd, K. K., Korostishevsky, M., Bonne-Tamir, B. Linkage of congenital, recessive deafness (DFNB4) to chromosome 7q31 and evidence for genetic heterogeneity in the Middle Eastern Druze population. Hum. Molec. Genet. 4: 1637-1642, 1995. [PubMed: 8541853, related citations] [Full Text]

  6. Baldwin, C. T. Personal Communication. Boston, Mass. 1998.

  7. Belenky, W. M., Madgy, D. N., Leider, J. S., Becker, C. J., Hotaling, A. J. The enlarged vestibular aqueduct syndrome (EVA syndrome). Ear Nose Throat J. 72: 746-751, 1993. [PubMed: 8261931, related citations]

  8. Campbell, C., Cucci, R. A., Prasad, S., Green, G. E., Edeal, J. B., Galer, C. E., Karniski, L. P., Sheffield, V. C., Smith, R. J. H. Pendred syndrome, DFNB4, and PDS/SLC26A4 identification of eight novel mutations and possible genotype-phenotype correlations. Hum. Mutat. 17: 403-411, 2001. [PubMed: 11317356, related citations] [Full Text]

  9. Chattaraj, P., Munjal, T., Honda, K., Rendtorff, N. D., Ratay, J. S., Muskett, J. A., Risso, D. S., Roux, I., Gertz, E. M., Schaffer, A. A., Friedman, T. B., Morell, R. J., Tranebjaerg, L., Griffith, A. J. A common SLC26A4-linked haplotype underlying non-syndromic hearing loss with enlargement of the vestibular aqueduct. J. Med. Genet. 54: 665-673, 2017. Note: Erratum: J. Med. Genet. 55: 846 only, 2018. Erratum: 6July, 2023. Advance Electronic Publication. [PubMed: 28780564, images, related citations] [Full Text]

  10. Choi, B. Y., Madeo, A. C., King, K. A., Zalewski, C. K., Pryor, S. P., Muskett, J. A., Nance, W. E., Butman, J. A., Brewer, C. C., Griffith, A. J. Segregation of enlarged vestibular aqueducts in families with non-diagnostic SLC26A4 genotypes. (Letter) J. Med. Genet. 46: 856-861, 2009. [PubMed: 19578036, images, related citations] [Full Text]

  11. Everett, L. A., Glaser, B., Beck, J. C., Idol, J. R., Buchs, A., Heyman, M., Adawi, F., Hazani, E., Nassir, E., Baxevanis, A. D., Sheffield, V. C., Green, E. D. Pendred syndrome is caused by mutations in a putative sulphate transporter gene (PDS). Nature Genet. 17: 411-422, 1997. [PubMed: 9398842, related citations] [Full Text]

  12. Fukushima, K., Ramesh, A., Srikumari Srisailapathy, C. R., Ni, L., Chen, A., O'Neill, M., Van Camp, G., Coucke, P., Smith, S. D., Kenyon, J. B., Jain, P., Wilcox, E. R., Zbar, R. I. S., Smith, R. J. H. Consanguineous nuclear families used to identify a new locus for recessive non-syndromic hearing loss on 14q. Hum. Molec. Genet. 4: 1643-1648, 1995. [PubMed: 8541854, related citations] [Full Text]

  13. Griffith, A. J., Arts, A., Downs, C., Innis, J. W., Shepard, N. T., Sheldon, S., Gebarski, S. S. Familial large vestibular aqueduct syndrome. Laryngoscope 106: 960-965, 1996. [PubMed: 8699909, related citations] [Full Text]

  14. Hu, H., Wu, L., Feng, Y., Pan, Q., Long, Z., Li, J., Dai, H., Xia, K., Liang, D., Niikawa, N., Xia, J. Molecular analysis of hearing loss associated with enlarged vestibular aqueduct in the mainland Chinese: a unique SLC26A4 mutation spectrum. J. Hum. Genet. 52: 492-497, 2007. [PubMed: 17443271, related citations] [Full Text]

  15. Jackler, R. K., De La Cruz, A. The large vestibular aqueduct syndrome. Laryngoscope 99: 1238-1243, 1989. [PubMed: 2601537, related citations] [Full Text]

  16. Levenson, M. J., Parisier, S. C., Jacobs, M., Edelstein, D. R. The large vestibular aqueduct syndrome in children: a review of 12 cases and the description of a new clinical entity. Arch. Otolaryng. Head Neck Surg. 115: 54-58, 1989. [PubMed: 2642380, related citations] [Full Text]

  17. Li, X. C., Everett, L. A., Lalwani, A. K., Desmukh, D., Friedman, T. B., Green, E. D., Wilcox, E. R. A mutation in PDS causes non-syndromic recessive deafness. (Letter) Nature Genet. 18: 215-217, 1998. [PubMed: 9500541, related citations] [Full Text]

  18. Okumura, T., Takahashi, H., Honjo, I., Takagi, A., Mitamura, K. Sensorineural hearing loss in patients with large vestibular aqueduct. Laryngoscope 105: 289-294, 1995. [PubMed: 7877418, related citations] [Full Text]

  19. Park, H.-J., Lee, S.-J., Jin, H.-S., Lee, J. O., Go, S.-H., Jang, H. S., Moon, S.-K., Lee, S.-C., Chun, Y.-M., Lee, H.-K., Choi, J.-Y., Jung, S.-C., Griffith, A. J., Koo, S. K. Genetic basis of hearing loss associated with enlarged vestibular aqueducts in Koreans. Clin. Genet. 67: 160-165, 2005. [PubMed: 15679828, related citations] [Full Text]

  20. Pourova, R., Janousek, P., Jurovcik, M., Dvorakova, M., Malikova, M., Raskova, D., Bendova, O., Leonardi, E., Murgia, A., Kabelka, Z., Astl, J., Seeman, P. Spectrum and frequency of SLC26A4 mutations among Czech patients with early hearing loss with and without enlarged vestibular aqueduct (EVA). Ann. Hum. Genet. 74: 299-307, 2010. [PubMed: 20597900, related citations] [Full Text]

  21. Pryor, S. P., Madeo, A. C., Reynolds, J. C., Sarlis, N. J., Arnos, K. S., Nance, W. E., Yang, Y., Zalewski, C. K., Brewer, C. C., Butman, J. A., Griffith, A. J. SLC26A4/PDS genotype-phenotype correlation in hearing loss with enlargement of the vestibular aqueduct (EVA): evidence that Pendred syndrome and non-syndromic EVA are distinct clinical and genetic entities. (Letter) J. Med. Genet. 42: 159-165, 2005. [PubMed: 15689455, related citations] [Full Text]

  22. Scott, D. A., Wang, R., Kreman, T. M., Andrews, M., McDonald, J. M., Bishop, J. R., Smith, R. J. H., Karniski, L. P., Sheffield, V. C. Functional differences of the PDS gene product are associated with phenotypic variation in patients with Pendred syndrome and non-syndromic hearing loss (DFNB4). Hum. Molec. Genet. 9: 1709-1715, 2000. [PubMed: 10861298, related citations] [Full Text]

  23. Tsukamoto, K., Suzuki, H., Harada, D., Namba, A., Abe, S., Usami, S. Distribution and frequencies of PDS (SLC26A4) mutations in Pendred syndrome and nonsyndromic hearing loss associated with enlarged vestibular aqueduct: a unique spectrum of mutations in Japanese. Europ. J. Hum. Genet. 11: 916-922, 2003. [PubMed: 14508505, related citations] [Full Text]

  24. Usami, S., Abe, S., Weston, M. D., Shinkawa, H., Van Camp, G., Kimberling, W. J. Non-syndromic hearing loss associated with enlarged vestibular aqueduct is caused by PDS mutations. Hum. Genet. 104: 188-192, 1999. [PubMed: 10190331, related citations] [Full Text]

  25. Valvassori, G. E. The large vestibular aqueduct and associated anomalies in the inner ear. Otolaryng. Clin. N. Am. 16: 95-101, 1983. [PubMed: 6602318, related citations]

  26. Wang, Q.-J., Zhao, Y.-L., Rao, S.-Q., Guo, Y.-F., Yuan, H., Zong, L., Guan, J., Xu, B.-C., Wang, D.-Y., Han, M.-K., Lan, L., Zhai, S.-Q., Shen, Y. A distinct spectrum of SLC26A4 mutations in patients with enlarged vestibular aqueduct in China. Clin. Genet. 72: 245-254, 2007. [PubMed: 17718863, related citations] [Full Text]

  27. Yang, T., Gurrola, J. G., II, Wu, H., Chiu, S. M., Wangemann, P., Snyder, P. M., Smith, R. J. H. Mutations of KCNJ10 together with mutations of SLC26A4 cause digenic nonsyndromic hearing loss associated with enlarged vestibular aqueduct syndrome. Am. J. Hum. Genet. 84: 651-657, 2009. [PubMed: 19426954, images, related citations] [Full Text]

  28. Yang, T., Vidarsson, H., Rodrigo-Blomqvist, S., Rosengren, S. S., Enerback, S., Smith, R. J. H. Transcriptional control of SLC26A4 is involved in Pendred syndrome and nonsyndromic enlargement of vestibular aqueduct (DFNB4). Am. J. Hum. Genet. 80: 1055-1063, 2007. Note: Erratum: Am. J. Hum. Genet. 81: 634 only, 2007. [PubMed: 17503324, images, related citations] [Full Text]


Ada Hamosh - updated : 03/06/2019
Cassandra L. Kniffin - updated : 6/12/2012
Marla J. F. O'Neill - updated : 2/15/2011
Ada Hamosh - updated : 10/6/2009
Marla J. F. O'Neill - updated : 6/1/2009
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Marla J. F. O'Neill - reorganized : 8/9/2007
Victor A. McKusick - updated : 8/6/2001
George E. Tiller - updated : 9/19/2000
Victor A. McKusick - updated : 2/24/1998
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# 600791

DEAFNESS, AUTOSOMAL RECESSIVE 4, WITH ENLARGED VESTIBULAR AQUEDUCT; DFNB4


Alternative titles; symbols

NEUROSENSORY NONSYNDROMIC RECESSIVE DEAFNESS 4; NSRD4
DILATED VESTIBULAR AQUEDUCT; DVA


ORPHA: 90636;   DO: 0110498;  


Phenotype-Gene Relationships

Location Phenotype Phenotype
MIM number
Inheritance Phenotype
mapping key
Gene/Locus Gene/Locus
MIM number
1q23.2 Enlarged vestibular aqueduct, digenic 600791 Autosomal recessive 3 KCNJ10 602208
5q35.1 Enlarged vestibular aqueduct 600791 Autosomal recessive 3 FOXI1 601093
7q22.3 Deafness, autosomal recessive 4, with enlarged vestibular aqueduct 600791 Autosomal recessive 3 SLC26A4 605646

TEXT

A number sign (#) is used with this entry because of evidence that autosomal recessive deafness-4 (DFNB4) with enlarged vestibular aqueduct (EVA) is caused by homozygous or compound heterozygous mutation in the SLC26A4 gene (605646) on chromosome 7q22.

Mutation in the FOXI1 gene (601093) has been found to be a rare cause of EVA. EVA may also be rarely caused by digenic inheritance of heterozygous mutations in the SLC26A4 and FOXI1 genes, or in the SLC26A4 and KCNJ10 (602208) genes.

Mutations in the SLC26A4 gene also cause Pendred syndrome (PDS; 274600), a disorder comprising congenital sensorineural hearing loss, cochlear abnormalities (EVA or Mondini dysplasia), and thyroid enlargement (goiter).


Description

DFNB4 with enlarged vestibular aqueduct is characterized by pre- or perilingual onset of sensorineural or mixed hearing loss, which may be fluctuating or progressive. The hearing loss is associated with temporal bone abnormalities, most commonly enlargement of the vestibular aqueduct, but it can also include the more severe Mondini dysplasia, a complex malformation in which the normal cochlear spiral of 2.5 turns is replaced by a hypoplastic coil of 1.5 turns (summary by Campbell et al., 2001 and Pryor et al., 2005). Enlarged vestibular aqueduct is the most common form of inner ear abnormality and can be associated with disequilibrium symptoms in a minority of patients (Valvassori, 1983; Jackler and de la Cruz, 1989; Levenson et al., 1989; Arcand et al., 1991; Belenky et al., 1993; Okumura et al., 1995).


Clinical Features

Griffith et al. (1996) reported a family in which 2 brothers had sensorineural hearing loss and enlarged vestibular aqueduct with no other abnormalities. Their parents were unaffected. The authors suggested autosomal recessive or X-linked inheritance with variable expressivity of the disorder in this family.

Abe et al. (1997) reported 3 families in which 2 sibs in each had congenital, high-frequency, fluctuating sensorineural hearing loss associated with enlargement of the vestibular aqueduct. Both parents in all 3 families were unaffected, suggesting autosomal recessive inheritance of the disorder.

Abe et al. (1999) studied 13 patients from 9 Japanese families and 2 patients from a Caucasian family who had congenital high frequency-dominant fluctuating sensorineural hearing loss and EVA on CT scan. Gadolidium-enhanced MRI confirmed the enlarged endolymphatic duct and sac. Hearing loss in some patient was progressive but with fluctuations, and about one-third had a history of vertigo. The perchlorate discharge test was performed in 8 patients from 6 of the families; all results were normal. Three of these families had been described previously by Abe et al. (1997).

Li et al. (1998) studied a large consanguineous family from southwest India in which 10 individuals ranging in age from 5 to 38 years were affected with congenital, profound, nonsyndromic autosomal recessive deafness. No goiter was palpable in any of the affected individuals and, although the perchlorate discharge test was not available, several other tests of thyroid function were normal. Axial and coronal computerized tomography of the temporal bone showed bilateral large vestibular aqueducts in all 3 affected individuals who were studied, with no Mondini-type cochlear malformation.


Mapping

Baldwin et al. (1995) described a large Middle-Eastern Druze family with recessive nonsyndromic deafness and demonstrated linkage between deafness in this family and 7q31 with a lod score exceeding 5.5. Baldwin et al. (1995) designated the locus DFNB4. In addition, they found that deafness in 3 other Druze pedigrees, including 1 related to the linked family, was not linked to 7q31. Thus, there appear to be multiple nonallelic mutations for deafness in this genetic isolate. On the basis of a personal communication from Baldwin (1998), Li et al. (1998) purported that the Israeli-Druze family indeed had Pendred syndrome. Affected members of this family were later found to have goiters.

Everett et al. (1997) identified SLC26A4 (605646) as the gene mutant in Pendred syndrome (PDS; 274600) in 3 families. The gene maps to 7q31. They pointed out that DFNB4 also maps to 7q31 and considered it likely that the DFNB4 individuals reported actually have PDS, rather than mutations in another gene.

By linkage analysis in 9 Japanese families and 1 Caucasian family with sensorineural hearing loss associated with EVA, Abe et al. (1999) localized the gene responsible to 7q31, with a maximum multipoint lod score of 3.647. The EVA candidate gene region was found to lie in a 1.7-cM interval between flanking markers D7S501 and D7S2425. Although this region overlaps the region containing the gene responsible for Pendred syndrome, these patients did not fulfill the criteria for PDS.


Molecular Genetics

Mutations in the SLC26A4 Gene

In affected members of a large consanguineous family from southwest India with DFNB4 with EVA, Li et al. (1998) found linkage to chromosome 7q31 and demonstrated that affected individuals were compound homozygotes for 2 mutations in exon 13 of the PDS gene (605646.0004).

Usami et al. (1999) screened the SLC26A4 gene for mutations in 6 families with congenital nonsyndromic high frequency, fluctuating, sometimes progressive sensorineural hearing loss, and enlarged vestibular aqueduct diagnosed by CT. One patient had a history of vertigo; none had Mondini malformation. Affected individuals in 4 of the 6 families were homozygous or compound heterozygous for SLC26A4 mutations (605646.0009-605646.0015).

Campbell et al. (2001) found mutations in the SLC26A4 gene in 5 of 6 multiplex families with EVA (83%) and in 4 of 5 multiplex families with Mondini dysplasia (80%), implying that mutations in the SLC26A4 gene are the major genetic cause of these temporal abnormalities. In their analyses of Pendred syndrome and DFNB4, they found that the 2 most common mutations, T416P (605646.0006) and IVS8+1G-A (605646.0007), were present in 22% and 30% of families, respectively.

Recessive mutations in the anion transporter gene SLC26A4 are known to be responsible for Pendred syndrome and for nonsyndromic hearing loss associated with EVA. However, a large percentage of patients with these phenotypes lack mutations in the SLC26A4 coding region in one or both alleles. Yang et al. (2007) identified and characterized a key transcriptional regulatory element in the SLC26A4 promoter that binds FOXI1 (601093), which is a transcriptional activator of SLC26A4. They found 9 patients with Pendred syndrome or nonsyndromic EVA who were heterozygous for a novel -103T-C mutation (605646.0027) in this regulatory element of the SLC26A4 gene that interfered with FOXI1 binding and completely abolished FOXI1-mediated transcriptional activation.

Mutation in the FOXI1 Gene

In 2 families given a diagnosis of enlarged vestibular aqueduct, Yang et al. (2007) found heterozygosity for a mutation in the FOXI1 gene (601093.0002). Although both of these families were classified by the authors as 'nonsyndromic EVA,' in one of them goiter reminiscent of Pendred syndrome was noted. Both alleles of the SLC26A4 gene were wildtype. The FOXI1 mutation showed significantly decreased luciferase activation in promoter-reporter assays, suggesting that this variant compromised the ability of FOXI1 to transactivate SLC26A4 and was causally related to disease.

Digenic Inheritance

Yang et al. (2007) reported a patient with DFNB4 and EVA who was compound heterozygous for a mutation in 2 different genes. The patient had a heterozygous mutation in the SLC26A4 gene (605646.0028) and a heterozygous mutation in the FOXI1 gene (601093.0001). This finding was consistent with their observation that EVA occurs in the mouse mutant doubly heterozygous for mutations in these 2 genes, and the results supported a dosage-dependent model for the molecular pathogenesis of nonsyndromic EVA that involves SLC26A4 and its transcriptional regulatory machinery. Yang et al. (2007) stated the this was the first example of digenic inheritance to be verified as a cause of human deafness.

Yang et al. (2009) sequenced the KCNJ10 gene (602208) in 89 patients who had a clinical diagnosis of EVA/Pendred syndrome and were known to carry only 1 SLC26A4 coding sequence mutation; promoter mutations and deletions of SLC26A4 were excluded in this patient cohort. In 2 patients, Yang et al. (2009) identified missense mutations in KCNJ10 (P194H, 602208.0008 and R348C, 602208.0009, respectively). The former patient carried a F335L mutation in SLC26A4 (605646.0031), and the latter a splice site mutation (605646.0029). Both KCNJ10 mutations reduce potassium conductance activity, which is critical for generating and maintaining the endocochlear potential.


Genotype/Phenotype Correlations

Scott et al. (2000) compared 3 common Pendred syndrome allele variants with 3 PDS mutations reported only in individuals with nonsyndromic hearing loss. The mutations associated with Pendred syndrome exhibited complete loss of pendrin (SLC26A4)-induced chloride and iodide transport, while alleles unique to patients with DFNB4 were able to transport both iodide and chloride, albeit at a much lower level than wildtype pendrin. The authors hypothesized that the residual level of anion transport was sufficient to eliminate or postpone the onset of goiter in individuals with DFNB4. They proposed a model for pendrin function in the thyroid in which pendrin transports iodide across the apical membrane of the thyrocyte into the colloid space.

Tsukamoto et al. (2003) screened 10 Japanese families with Pendred syndrome, 32 Japanese families with bilateral sensorineural hearing loss associated with EVA, and 96 unrelated Japanese controls for mutations in the SLC26A4 gene. They identified causative mutations in 90% of the typical Pendred syndrome families and in 78.1% of those with sensorineural hearing loss with EVA. None of their patients had the Mondini malformation. Tsukamoto et al. (2003) noted that the same combination of mutations resulted in variable phenotypic expression (see, e.g., 605646.0011 and 605646.0012), suggesting that these 2 conditions are part of a continuous spectrum of disease.

Pryor et al. (2005) evaluated the clinical phenotype and SLC26A4 genotype of 39 patients with EVA from 31 families, definitively classifying 29 individuals. All 11 PDS patients had 2 mutant SLC26A4 alleles, whereas all 18 nonsyndromic EVA patients had either 1 or no SLC26A4 mutant alleles. Pryor et al. (2005) concluded that PDS and nonsyndromic EVA are distinct clinical and genetic entities, with PDS being a genetically homogeneous disorder caused by biallelic SLC26A4 mutations, and at least some cases of nonsyndromic EVA being associated with a single SLC26A4 mutation. They noted that the detection of a single mutant SLC26A4 allele is incompletely diagnostic without additional clinical evaluation to differentiate PDS from nonsyndromic EVA.

Albert et al. (2006) analyzed the SLC26A4 gene in 109 patients from 100 unrelated French Caucasian families with nonsyndromic deafness and enlarged vestibular aqueduct and no mutation in the GJB2 gene (121011). They identified 91 allelic variants in 40 unrelated families (prevalence of SLC26A4 mutations, 40%). There were 18 compound heterozygous and 6 homozygous families; Albert et al. (2006) noted that patients with biallelic mutations had more severe deafness, an earlier age of diagnosis, and a more fluctuating course than patients in whom no mutation was identified. Albert et al. (2006) estimated that up to 4% of nonsyndromic hearing impairment could be caused by SLC26A4 mutations.

In 71 families with EVA, Choi et al. (2009) used sequence analysis of SLC26A4 coding and conserved noncoding regions and CGH microarray analysis, and compared segregation of EVA among families with 2, 1, or no detectable mutant alleles of SLC26A4. EVA segregation ratios were similar in families with 1 or 2 mutant alleles, but the segregation ratio for families with 1 mutation was significantly higher than that of families with no SLC26A4 mutations. Haplotype analyses revealed discordant segregation of EVA with SLC26A4-linked STR markers in 8 of 24 families with no mutation in SLC26A4. Choi et al. (2009) concluded that families with EVA and 1 detectable mutation in SLC26A4 were likely to be segregating EVA as a trait caused by that mutation in combination with a second occult mutant allele of SLC26A4 or of another autosomal gene. In contrast, EVA appeared to be a nongenetic or complex trait with a significantly lower recurrence rate in families with no detectable SLC26A4 mutation.

Chattaraj et al. (2017) performed genotype-haplotype analysis and massively parallel sequencing of the SLC26A4 gene in patients with EVA and only 1 detected mutant allele in the SLC26A4 gene. The authors identified a shared novel haplotype, termed CEVA (Caucasian EVA), composed of 12 uncommon variants upstream of SLC26A4. The presence of the CEVA haplotype on 7 of 10 mutation-negative chromosomes in a National Institutes of Health discovery cohort and 6 of 6 mutation-negative chromosomes in a Danish replication cohort was higher than the observed prevalence of 28 of 1,006 Caucasian control chromosomes (p less than 0.0001 for each EVA cohort). The corresponding heterozygous carrier rate was 28 of 503 (5.6%). The prevalence of CEVA (11 of 126) was also increased among EVA chromosomes with no mutations detected (p = 0.0042). Chattaraj et al. (2017) concluded that the CEVA haplotype causally contributes to most cases of Caucasian EVA, being present in cases where only 1 mutation is detected by traditional exonic sequencing, and possibly in some cases where no mutation has been detected.


Population Genetics

Wang et al. (2007) identified a total of 40 SLC26A4 mutations, including 25 novel mutations, among 107 Chinese patients with EVA from 101 families. Overall, SLC26A4 mutations were identified in 97.9% of patients. The most common mutation was a splice site transition (IVS7-2A-G; 605646.0029), which accounted for 57.6% of mutant alleles. Park et al. (2005) identified the same splice site mutation in 9 (20%) of 45 mutant alleles in a study of Korean EVA patients. In 15 patients from 13 unrelated Chinese families with deafness and EVA, Hu et al. (2007) identified the IVS7-2A-G mutation in 5 (22.3%) of 22 mutant alleles. Reviewing previously published studies involving Chinese patients, the authors stated that IVS7-2A-G accounted for 69.1% (76 of 110) of all mutant alleles in the Chinese, suggesting a founder effect.

Pourova et al. (2010) screened the SLC26A4 gene in 303 Czech patients with early-onset hearing loss. The patients were divided into 3 groups: 22 with EVA and/or Mondini malformation on imaging, 220 patients without imaging available, and 61 patients with EVA/Mondini-negative imaging studies. Biallelic SLC26A4 mutations were found in 6 (27.3%) patients in the first group, 2 (0.9%) patients in the second group, and none (0%) in the third group; 4 of the 8 patients with biallelic mutations had goiter, consistent with Pendred syndrome. Monoallelic SLC26A4 mutations were found in 3 (13.6%) patients in the first group, 12 (5.5%) patients in the second group, and 3 (4.9%) patients in the third group. The most frequent mutations were V138F (605646.0024) and L445W (605646.0018), in 18% and 8.9% alleles, respectively. Among 13 patients with bilateral EVA, 6 (46%) carried biallelic mutations. No biallelic mutations were found in EVA-negative patients, but 4.9% had monoallelic mutations. Overall, biallelic mutations were found in only 2.7% of all patients, but were more common in familial cases. The findings also suggested that a single SLC26A4 mutation may contribute to the phenotype, perhaps in concert with mutations in other genes.


Nomenclature

In the title of their paper, Baldwin et al. (1995) referred to the form of deafness that maps to 7q31 as DFNB4. The same symbol was used by Fukushima et al. (1995) for a locus on chromosome 14 (600792). The chromosome 14 locus is, in fact, symbolized DFNB5.


REFERENCES

  1. Abe, S., Usami, S., Hoover, D. M., Cohn, E., Shinkawa, H., Kimberling, W. J. Fluctuating sensorineural hearing loss associated with enlarged vestibular aqueduct maps to 7q31, the region containing the Pendred gene. Am. J. Med. Genet. 82: 322-328, 1999. [PubMed: 10051166]

  2. Abe, S., Usami, S., Shinkawa, H. Three familial cases of hearing loss associated with enlargement of the vestibular aqueduct. Ann. Otol. Rhinol. Laryng. 106: 1063-1069, 1997. [PubMed: 9415602] [Full Text: https://doi.org/10.1177/000348949710601210]

  3. Albert, S., Blons, H., Jonard, L., Feldmann, D., Chauvin, P., Loundon, N., Sergent-Allaoui, A., Houang, M., Joannard, A., Schmerber, S., Delobel, B., Leman, J., and 18 others. SLC26A4 gene is frequently involved in nonsyndromic hearing impairment with enlarged vestibular aqueduct in Caucasian populations. Europ. J. Hum. Genet. 14: 773-779, 2006. [PubMed: 16570074] [Full Text: https://doi.org/10.1038/sj.ejhg.5201611]

  4. Arcand, P., Desrosiers, M., Dube, J., Abela, A. The large vestibular aqueduct syndrome and sensorineural hearing loss in the pediatric population. J. Otolaryng. 20: 247-250, 1991. [PubMed: 1920576]

  5. Baldwin, C. T., Weiss, S., Farrer, L., De Stefano, A., Adair, R., Franklyn, B., Kidd, K. K., Korostishevsky, M., Bonne-Tamir, B. Linkage of congenital, recessive deafness (DFNB4) to chromosome 7q31 and evidence for genetic heterogeneity in the Middle Eastern Druze population. Hum. Molec. Genet. 4: 1637-1642, 1995. [PubMed: 8541853] [Full Text: https://doi.org/10.1093/hmg/4.9.1637]

  6. Baldwin, C. T. Personal Communication. Boston, Mass. 1998.

  7. Belenky, W. M., Madgy, D. N., Leider, J. S., Becker, C. J., Hotaling, A. J. The enlarged vestibular aqueduct syndrome (EVA syndrome). Ear Nose Throat J. 72: 746-751, 1993. [PubMed: 8261931]

  8. Campbell, C., Cucci, R. A., Prasad, S., Green, G. E., Edeal, J. B., Galer, C. E., Karniski, L. P., Sheffield, V. C., Smith, R. J. H. Pendred syndrome, DFNB4, and PDS/SLC26A4 identification of eight novel mutations and possible genotype-phenotype correlations. Hum. Mutat. 17: 403-411, 2001. [PubMed: 11317356] [Full Text: https://doi.org/10.1002/humu.1116]

  9. Chattaraj, P., Munjal, T., Honda, K., Rendtorff, N. D., Ratay, J. S., Muskett, J. A., Risso, D. S., Roux, I., Gertz, E. M., Schaffer, A. A., Friedman, T. B., Morell, R. J., Tranebjaerg, L., Griffith, A. J. A common SLC26A4-linked haplotype underlying non-syndromic hearing loss with enlargement of the vestibular aqueduct. J. Med. Genet. 54: 665-673, 2017. Note: Erratum: J. Med. Genet. 55: 846 only, 2018. Erratum: 6July, 2023. Advance Electronic Publication. [PubMed: 28780564] [Full Text: https://doi.org/10.1136/jmedgenet-2017-104721]

  10. Choi, B. Y., Madeo, A. C., King, K. A., Zalewski, C. K., Pryor, S. P., Muskett, J. A., Nance, W. E., Butman, J. A., Brewer, C. C., Griffith, A. J. Segregation of enlarged vestibular aqueducts in families with non-diagnostic SLC26A4 genotypes. (Letter) J. Med. Genet. 46: 856-861, 2009. [PubMed: 19578036] [Full Text: https://doi.org/10.1136/jmg.2009.067892]

  11. Everett, L. A., Glaser, B., Beck, J. C., Idol, J. R., Buchs, A., Heyman, M., Adawi, F., Hazani, E., Nassir, E., Baxevanis, A. D., Sheffield, V. C., Green, E. D. Pendred syndrome is caused by mutations in a putative sulphate transporter gene (PDS). Nature Genet. 17: 411-422, 1997. [PubMed: 9398842] [Full Text: https://doi.org/10.1038/ng1297-411]

  12. Fukushima, K., Ramesh, A., Srikumari Srisailapathy, C. R., Ni, L., Chen, A., O'Neill, M., Van Camp, G., Coucke, P., Smith, S. D., Kenyon, J. B., Jain, P., Wilcox, E. R., Zbar, R. I. S., Smith, R. J. H. Consanguineous nuclear families used to identify a new locus for recessive non-syndromic hearing loss on 14q. Hum. Molec. Genet. 4: 1643-1648, 1995. [PubMed: 8541854] [Full Text: https://doi.org/10.1093/hmg/4.9.1643]

  13. Griffith, A. J., Arts, A., Downs, C., Innis, J. W., Shepard, N. T., Sheldon, S., Gebarski, S. S. Familial large vestibular aqueduct syndrome. Laryngoscope 106: 960-965, 1996. [PubMed: 8699909] [Full Text: https://doi.org/10.1097/00005537-199608000-00009]

  14. Hu, H., Wu, L., Feng, Y., Pan, Q., Long, Z., Li, J., Dai, H., Xia, K., Liang, D., Niikawa, N., Xia, J. Molecular analysis of hearing loss associated with enlarged vestibular aqueduct in the mainland Chinese: a unique SLC26A4 mutation spectrum. J. Hum. Genet. 52: 492-497, 2007. [PubMed: 17443271] [Full Text: https://doi.org/10.1007/s10038-007-0139-0]

  15. Jackler, R. K., De La Cruz, A. The large vestibular aqueduct syndrome. Laryngoscope 99: 1238-1243, 1989. [PubMed: 2601537] [Full Text: https://doi.org/10.1288/00005537-198912000-00006]

  16. Levenson, M. J., Parisier, S. C., Jacobs, M., Edelstein, D. R. The large vestibular aqueduct syndrome in children: a review of 12 cases and the description of a new clinical entity. Arch. Otolaryng. Head Neck Surg. 115: 54-58, 1989. [PubMed: 2642380] [Full Text: https://doi.org/10.1001/archotol.1989.01860250056026]

  17. Li, X. C., Everett, L. A., Lalwani, A. K., Desmukh, D., Friedman, T. B., Green, E. D., Wilcox, E. R. A mutation in PDS causes non-syndromic recessive deafness. (Letter) Nature Genet. 18: 215-217, 1998. [PubMed: 9500541] [Full Text: https://doi.org/10.1038/ng0398-215]

  18. Okumura, T., Takahashi, H., Honjo, I., Takagi, A., Mitamura, K. Sensorineural hearing loss in patients with large vestibular aqueduct. Laryngoscope 105: 289-294, 1995. [PubMed: 7877418] [Full Text: https://doi.org/10.1288/00005537-199503000-00012]

  19. Park, H.-J., Lee, S.-J., Jin, H.-S., Lee, J. O., Go, S.-H., Jang, H. S., Moon, S.-K., Lee, S.-C., Chun, Y.-M., Lee, H.-K., Choi, J.-Y., Jung, S.-C., Griffith, A. J., Koo, S. K. Genetic basis of hearing loss associated with enlarged vestibular aqueducts in Koreans. Clin. Genet. 67: 160-165, 2005. [PubMed: 15679828] [Full Text: https://doi.org/10.1111/j.1399-0004.2004.00386.x]

  20. Pourova, R., Janousek, P., Jurovcik, M., Dvorakova, M., Malikova, M., Raskova, D., Bendova, O., Leonardi, E., Murgia, A., Kabelka, Z., Astl, J., Seeman, P. Spectrum and frequency of SLC26A4 mutations among Czech patients with early hearing loss with and without enlarged vestibular aqueduct (EVA). Ann. Hum. Genet. 74: 299-307, 2010. [PubMed: 20597900] [Full Text: https://doi.org/10.1111/j.1469-1809.2010.00581.x]

  21. Pryor, S. P., Madeo, A. C., Reynolds, J. C., Sarlis, N. J., Arnos, K. S., Nance, W. E., Yang, Y., Zalewski, C. K., Brewer, C. C., Butman, J. A., Griffith, A. J. SLC26A4/PDS genotype-phenotype correlation in hearing loss with enlargement of the vestibular aqueduct (EVA): evidence that Pendred syndrome and non-syndromic EVA are distinct clinical and genetic entities. (Letter) J. Med. Genet. 42: 159-165, 2005. [PubMed: 15689455] [Full Text: https://doi.org/10.1136/jmg.2004.024208]

  22. Scott, D. A., Wang, R., Kreman, T. M., Andrews, M., McDonald, J. M., Bishop, J. R., Smith, R. J. H., Karniski, L. P., Sheffield, V. C. Functional differences of the PDS gene product are associated with phenotypic variation in patients with Pendred syndrome and non-syndromic hearing loss (DFNB4). Hum. Molec. Genet. 9: 1709-1715, 2000. [PubMed: 10861298] [Full Text: https://doi.org/10.1093/hmg/9.11.1709]

  23. Tsukamoto, K., Suzuki, H., Harada, D., Namba, A., Abe, S., Usami, S. Distribution and frequencies of PDS (SLC26A4) mutations in Pendred syndrome and nonsyndromic hearing loss associated with enlarged vestibular aqueduct: a unique spectrum of mutations in Japanese. Europ. J. Hum. Genet. 11: 916-922, 2003. [PubMed: 14508505] [Full Text: https://doi.org/10.1038/sj.ejhg.5201073]

  24. Usami, S., Abe, S., Weston, M. D., Shinkawa, H., Van Camp, G., Kimberling, W. J. Non-syndromic hearing loss associated with enlarged vestibular aqueduct is caused by PDS mutations. Hum. Genet. 104: 188-192, 1999. [PubMed: 10190331] [Full Text: https://doi.org/10.1007/s004390050933]

  25. Valvassori, G. E. The large vestibular aqueduct and associated anomalies in the inner ear. Otolaryng. Clin. N. Am. 16: 95-101, 1983. [PubMed: 6602318]

  26. Wang, Q.-J., Zhao, Y.-L., Rao, S.-Q., Guo, Y.-F., Yuan, H., Zong, L., Guan, J., Xu, B.-C., Wang, D.-Y., Han, M.-K., Lan, L., Zhai, S.-Q., Shen, Y. A distinct spectrum of SLC26A4 mutations in patients with enlarged vestibular aqueduct in China. Clin. Genet. 72: 245-254, 2007. [PubMed: 17718863] [Full Text: https://doi.org/10.1111/j.1399-0004.2007.00862.x]

  27. Yang, T., Gurrola, J. G., II, Wu, H., Chiu, S. M., Wangemann, P., Snyder, P. M., Smith, R. J. H. Mutations of KCNJ10 together with mutations of SLC26A4 cause digenic nonsyndromic hearing loss associated with enlarged vestibular aqueduct syndrome. Am. J. Hum. Genet. 84: 651-657, 2009. [PubMed: 19426954] [Full Text: https://doi.org/10.1016/j.ajhg.2009.04.014]

  28. Yang, T., Vidarsson, H., Rodrigo-Blomqvist, S., Rosengren, S. S., Enerback, S., Smith, R. J. H. Transcriptional control of SLC26A4 is involved in Pendred syndrome and nonsyndromic enlargement of vestibular aqueduct (DFNB4). Am. J. Hum. Genet. 80: 1055-1063, 2007. Note: Erratum: Am. J. Hum. Genet. 81: 634 only, 2007. [PubMed: 17503324] [Full Text: https://doi.org/10.1086/518314]


Contributors:
Ada Hamosh - updated : 03/06/2019
Cassandra L. Kniffin - updated : 6/12/2012
Marla J. F. O'Neill - updated : 2/15/2011
Ada Hamosh - updated : 10/6/2009
Marla J. F. O'Neill - updated : 6/1/2009
Cassandra L. Kniffin - updated : 10/26/2007
Marla J. F. O'Neill - reorganized : 8/9/2007
Victor A. McKusick - updated : 8/6/2001
George E. Tiller - updated : 9/19/2000
Victor A. McKusick - updated : 2/24/1998
Victor A. McKusick - updated : 12/2/1997

Creation Date:
Victor A. McKusick : 9/25/1995

Edit History:
alopez : 02/15/2024
alopez : 01/26/2024
alopez : 01/26/2024
carol : 10/12/2023
carol : 08/24/2023
carol : 03/07/2019
alopez : 03/06/2019
carol : 06/21/2016
carol : 2/12/2016
alopez : 6/13/2012
ckniffin : 6/12/2012
carol : 4/24/2012
terry : 3/26/2012
wwang : 2/17/2011
terry : 2/15/2011
carol : 1/10/2011
alopez : 10/27/2009
alopez : 10/13/2009
terry : 10/6/2009
alopez : 7/31/2009
wwang : 6/2/2009
terry : 6/1/2009
terry : 12/12/2008
wwang : 11/7/2007
ckniffin : 10/26/2007
alopez : 8/9/2007
carol : 8/6/2001
alopez : 2/20/2001
alopez : 9/19/2000
alopez : 9/19/2000
dkim : 11/6/1998
alopez : 5/28/1998
alopez : 2/27/1998
terry : 2/24/1998
jenny : 12/2/1997
mark : 7/3/1997
mimadm : 11/3/1995
mark : 9/25/1995