* 114190

CALCITONIN RECEPTOR-LIKE RECEPTOR; CALCRL


Alternative titles; symbols

CALCR; CRLR
CALCITONIN RECEPTOR-LIKE GENE
CALCITONIN GENE-RELATED PEPTIDE RECEPTOR; CGRPR


HGNC Approved Gene Symbol: CALCRL

Cytogenetic location: 2q32.1     Genomic coordinates (GRCh38): 2:187,341,964-187,448,252 (from NCBI)


Gene-Phenotype Relationships
Location Phenotype Phenotype
MIM number
Inheritance Phenotype
mapping key
2q32.1 ?Lymphatic malformation 8 618773 AR 3

TEXT

Description

The CALCRL gene encodes a G protein-coupled receptor (GPCR) that forms an active signaling complex for either adrenomedullin (ADM; 103275) or calcitonin gene-related peptide (CGRP; see 114130), depending on the receptor's interaction with RAMP proteins. Interaction of CALCRL with RAMP2 (605154) or RAMP3 (605155) leads to the formation of a receptor complex that binds ADM, whereas interaction with RAMP1 (605153) creates the active form of the CGRP-binding receptor. These 2 signaling pathways have different functions (summary by Mackie et al., 2018).


Cloning and Expression

Studies of the structure and expression of the calcitonin gene (CALCA; 114130) have demonstrated the generation of alternative mRNA species from a single gene in a tissue-specific manner. The mRNA species produced encode polyproteins cleaved by posttranslational events to yield either calcitonin (CT), the major gene product in the thyroid, or a predicted 37-amino acid amidated peptide, the calcitonin gene-related peptide (CGRP, or CGRP1). A second gene encoding a similar peptide (CGRP2, or CALCB; 114160) has been identified in man as well as in the rat. Receptors for CGRP have been located in the central nervous system by receptor-binding studies and visualized by optoradiography. Foord and Craig (1987) described the identification and purification of a receptor for CGRP in human term placenta.

By screening a cerebellum cDNA library with degenerate PCR primers corresponding to the rat calcitonin receptor-like receptor (Crlr) sequence, Fluhmann et al. (1995) isolated a cDNA encoding CGRPR, which they called CRLS (calcitonin receptor-like sequence). The deduced 461-amino acid CGRPR protein shares 91% amino acid identity with rat Crlr and 55% identity with CALCR. Northern blot analysis detected a major 5.2-kb CGRPR transcript and minor 7.3- and 3.4-kb CGRPR transcripts in heart, lung, and kidney; lower expression of the 5.2-kb transcript was detected in brain and placenta. Expression of CGRPR did not, however, confer binding of CT or CGRP, nor did it alter cyclic AMP accumulation in response to CT, CGRP, CGRP2, adrenomedullin (ADM; 103275), or amylin (IAPP; 147940).

Aiyar et al. (1996) cloned a cDNA encoding CGRPR, which shares significant peptide sequence homology with CALCR, a member of the G protein-coupled receptor superfamily. CGRPR is predominantly expressed in the lung and heart.


Gene Function

In a mammalian cell line without an endogenous receptor, McLatchie et al. (1998) observed increased intracellular cAMP levels in response to CGRP when CGRPR and receptor activity-modifying protein-1 (RAMP1; 605153) were expressed together, but not when they were expressed alone. Flow cytometric analysis showed that expression of CGRPR at the cell surface increases substantially when CGRPR is expressed with RAMP1. Likewise, surface expression of RAMP1 was shown to increase in cells also expressing CGRPR. SDS-PAGE analysis showed that binding of CGRP requires expression of both the 14-kD RAMP1 and the 58-kD CGRPR glycoprotein. The authors demonstrated that in the presence of RAMP1, CGRPR becomes a 66-kD terminally glycosylated protein. McLatchie et al. (1998) found that unlike RAMP1, RAMP2 (605154) and RAMP3 (605155) do not potentiate responses to CGRP but do transport the glycosylated 58-kD but not the 66-kD form of CGRPR to the cell surface. In frog oocytes and mammalian cells, coexpression of RAMP2 and CGRPR resulted in increased intracellular cAMP concentrations in response to ADM but not to CGRP, CT, or IAPP. SDS-PAGE analysis demonstrated that ADM binds to coexpressed RAMP2 and CGRPR.

By RT-PCR analysis, Kamitani et al. (1999) found coexpression of RAMP2 and CGRPR in endothelial and smooth muscle cells. They confirmed that the intracellular cAMP concentration increases in response to ADM in endothelial and smooth muscle cells coexpressing RAMP2 and CGRPR.

Foord and Marshall (1999) reviewed the roles of CGRPR and the RAMPs in mediating responses to peptides related to calcitonin. They stated that RAMPs transport CGRPR to the cell surface, define its pharmacology, and determine its glycosylation state. CALCRL is thus an ADM receptor when united with RAMP2, and a calcitonin gene-related peptide receptor when united with RAMP1.

McLatchie et al. (1998) demonstrated that a complex consisting of RAMP2 and CALCRL can function as an ADM receptor. To investigate whether ADM has implications as a pathophysiologic substance in pregnancy-induced hypertension, Makino et al. (2001) measured the changes of expression of RAMP2 and CALCRL in fetomaternal tissues in normotensive pregnant women and pregnancy-induced hypertensive women by Northern blot analysis. RAMP2 and CALCRL mRNA was significantly decreased in the umbilical artery and uterus of the patients with pregnancy-induced hypertension. On the other hand, RAMP2 mRNA was significantly increased in the fetal membrane of the patients with pregnancy-induced hypertension. In addition, there was a significant negative correlation between the RAMP2 mRNA levels in the umbilical artery and uterine muscle and blood pressure. However, there was no correlation between the mRNA level and blood pressure in fetal membrane and placenta, suggesting that there is no close relationship to the pathogenesis in pregnancy-induced hypertension. These findings suggested that the reduced expression of RAMP2 and CALCRL functioning as components of an adrenomedullin receptor in umbilical artery and uterus may have some role in pregnancy-induced hypertension.

Using monocyte-derived Langerhans cells (LCs) and a macrophage-tropic (see CCR5, 601373) human immunodeficiency virus (HIV)-1 (see 609423) molecular clone, Ganor et al. (2013) showed that CGRP acted via CRLR expressed on LCs and interfered with multiple steps of LC-mediated HIV-1 transmission. CGRP increased langerin (CD207; 604862) expression while decreasing that of selected integrins, such as CD1A (188370), CD11C (ITGAX; 151510), and DCSIGN (CD209; 604672). CGRP also activated NFKB (see 164011), resulting in decreased intracellular HIV-1, limited LC-T cell conjugate formation, and elevated secretion of the CCR5-binding chemokine CCL3 (182283). These mechanisms efficiently inhibited HIV-1 transfer from LCs to T cells. Compared with healthy humans and macaques, HIV-1 infection resulted in decreased plasma CGRP levels that could be reversed by highly active antiretroviral treatment (HAART, see 609423). Ganor et al. (2013) concluded that CGRP acts at molecular and cellular levels to limit mucosal HIV-1 transmission and that CRLR agonists may have therapeutic potential.


Gene Structure

Nakazawa et al. (2001) demonstrated that the CALCRL gene contains 15 exons and spans more then 103 kb of genomic DNA.


Mapping

Stumpf (2020) mapped the CALCRL gene to chromosome 2q32.1 based on an alignment of the CALCRL sequence (GenBank U17473.1) with the genomic sequence (GRCh38).


Biochemical Features

Cryoelectron Microscopy

Liang et al. (2018) reported the structure of the human CGRP (see 114130) receptor, a heterodimer of CALCRL and receptor activity-modifying protein-1 (RAMP1; 605153), in complex with CGRP and a Gs-protein heterotrimer at 3.3-angstrom global resolution, determined by cryoelectron microscopy. The RAMP1 transmembrane domain sits at the interface between transmembrane domains 3, 4, and 5 of CALCRL, and stabilizes CALCRL extracellular loop 2. RAMP1 makes only limited direct contact with CGRP, consistent with its function in allosteric modulation of CALCRL. Molecular dynamics simulations indicated that RAMP1 provides stability to the receptor complex, particularly in the positioning of the extracellular domain of CALCRL.


Molecular Genetics

In a 22-week-old male fetus, conceived of consanguineous parents, with hydrops fetalis due to lymphatic malformation (LMPHM8; 618773), Mackie et al. (2018) identified a homozygous in-frame deletion in the CALCRL gene (Val205del; 114190.0001). The mutation, which was found by exome sequencing and confirmed by Sanger sequencing, segregated with the disorder in the family. The variant was not found in the 1000 Genomes Project, Exome Sequencing Project, ExAC, or gnomAD databases. In the family, 3 female carriers of the mutation had reduced fertility associated with recurrent miscarriages; there were 8 total miscarriages among the 3 women, and 2 of the miscarriages were confirmed to be due to hydrops fetalis. In vitro functional expression studies in HEK293 cells showed that the mutant protein had reduced association with RAMP2, reduced translocation to the plasma membrane, and impaired signaling activity compared to wildtype. The findings were consistent with a specific loss-of-function effect targeting the CALCRL-RAMP2-ADM signaling pathway, which is essential for normal lymphangiogenesis.


Animal Model

Mackie et al. (2018) found that global deletion of the Calcrl gene in mice resulted in mid-gestation embryonic lethality with profound interstitial edema due to arrested lymphangiogenesis. The placentas from Calcrl-null mice showed marked interstitial edema within the labyrinth and enlarged junctional zone. Targeted deletion of the Calcrl gene in lymphatic endothelial cells also caused embryonic lethality with profound interstitial and subcutaneous edema. Histologic analysis showed small lymphatic vessels that were developmentally arrested, as well as dilated and malformed lymphatic capillaries compared to controls. The phenotype was similar to that observed in both Adm-null and Ramp2-null mice, confirming that the CALCRL-RAMP2-ADM signaling pathway is essential for normal lymphangiogenesis.


ALLELIC VARIANTS ( 1 Selected Example):

.0001 LYMPHATIC MALFORMATION 8 (1 family)

CALCRL, 3-BP DEL, NT614
  
RCV001003344

In a 22-week-old male fetus, conceived of consanguineous Arab parents, with hydrops fetalis due to lymphatic malformation-8 (LMPHM8; 618773), Mackie et al. (2018) identified a homozygous 3-bp in-frame deletion (c.614_616del, NM_005795.5) in exon 9 of the CALCRL gene, resulting in deletion of the highly conserved residue Val205 (V205del) in extracellular loop 1. The mutation, which was found by exome sequencing and confirmed by Sanger sequencing, segregated with the disorder in the family. The variant was not found in the 1000 Genomes Project, Exome Sequencing Project, ExAC, or gnomAD databases. In the family, 3 female carriers of the mutation had reduced fertility associated with recurrent miscarriages; there were 8 total miscarriages among the 3 women, and 2 of the miscarriages were confirmed to be due to hydrops fetalis. In vitro functional expression studies in HEK293 cells showed that the mutant protein had reduced association with RAMP2 (605154), reduced translocation to the plasma membrane, and impaired signaling activity compared to wildtype. The findings were consistent with a specific loss-of-function effect targeting the CALCRL-RAMP2-ADM (103275) signaling pathway, which is essential for normal lymphangiogenesis. The fetus was also homozygous for a missense R349G variant in the ASAH1 gene (613468), which is associated with Farber lipogranulomatosis (FRBRL; 228000). FRBRL can sometimes present with antenatal hydrops fetalis; however, other clinical manifestations of FRBRL were not present in the fetus or in other nongenotyped families members.


REFERENCES

  1. Aiyar, N., Rand, K., Elshourbagy, N. A., Zeng, Z., Adamou, J. E., Bergsma, D. J., Li, Y. A cDNA encoding the calcitonin gene-related peptide type 1 receptor. J. Biol. Chem. 271: 11325-11329, 1996. [PubMed: 8626685, related citations] [Full Text]

  2. Fluhmann, B., Muff, R., Hunziker, W., Fischer, J. A., Born, W. A human orphan calcitonin receptor-like structure. Biochem. Biophys. Res. Commun. 206: 341-347, 1995. [PubMed: 7818539, related citations] [Full Text]

  3. Foord, S. M., Craig, R. K. Isolation and characterisation of a human calcitonin-gene-related-peptide receptor. Europ. J. Biochem. 170: 373-379, 1987. [PubMed: 2826160, related citations] [Full Text]

  4. Foord, S. M., Marshall, F. H. RAMPs: accessory proteins for seven transmembrane domain receptors. Trends Pharm. Sci. 20: 184-187, 1999. [PubMed: 10354609, related citations] [Full Text]

  5. Ganor, Y., Drillet-Dangeard, A.-S., Lopalco, L., Tudor, D., Tambussi, G., Delongchamps, N. B., Zerbib, M., Bomsel, M. Calcitonin gene-related peptide inhibits Langerhans cell-mediated HIV-1 transmission. J. Exp. Med. 210: 2161-2170, 2013. [PubMed: 24081951, images, related citations] [Full Text]

  6. Kamitani, S., Asakawa, M., Shimekake, Y., Kuwasako, K., Nakahara, K., Sakata, T. The RAMP2/CRLR complex is a functional adrenomedullin receptor in human endothelial and vascular smooth muscle cells. FEBS Lett. 448: 111-114, 1999. [PubMed: 10217420, related citations] [Full Text]

  7. Liang, Y.-L., Khoshouei, M., Deganutti, G., Glukhova, A., Koole, C., Peat, T. S., Radjainia, M., Plitzko, J. M., Baumeister, W., Miller, L. J., Hay, D. L., Christopoulos, A., Reynolds, C. A., Wootten, D., Sexton, P. M. Cryo-EM structure of the active, Gs-protein complexed, human CGRP receptor. Nature 561: 492-497, 2018. [PubMed: 30209400, related citations] [Full Text]

  8. Mackie, D. I., Al Mutairi, F., Davis, R. B., Kechele, D. L., Nielsen, N. R., Snyder, J. C., Caron, M. G., Kliman, H. J., Berg, J. S., Simms, J., Poyner, D. R., Caron, K. M. hCALCRL mutation causes autosomal recessive nonimmune hydrops fetalis with lymphatic dysplasia. J. Exp. Med. 215: 2339-2353, 2018. [PubMed: 30115739, related citations] [Full Text]

  9. Makino, Y., Shibata, K., Makino, I., Kangawa, K., Kawarabayashi, T. Alteration of the adrenomedullin receptor components gene expression associated with the blood pressure in pregnancy-induced hypertension. J. Clin. Endocr. Metab. 86: 5079-5082, 2001. [PubMed: 11600589, related citations] [Full Text]

  10. McLatchie, L. M., Fraser, N. J., Main, M. J., Wise, A., Brown, J., Thompson, N., Solari, R., Lee, M. G., Foord, S. M. RAMPs regulate the transport and ligand specificity of the calcitonin-receptor-like receptor. Nature 393: 333-339, 1998. [PubMed: 9620797, related citations] [Full Text]

  11. Nakazawa, I., Nakajima, T., Harada, H., Ishigami, T., Umemura, S., Emi, M. Human calcitonin receptor-like receptor for adrenomedullin: genomic structure, eight single-nucleotide polymorphisms, and haplotype analysis. J. Hum. Genet. 46: 132-136, 2001. [PubMed: 11310580, related citations] [Full Text]

  12. Stumpf, A. M. Personal Communication. Baltimore, Md. 02/13/2020.


Cassandra L. Kniffin - updated : 02/10/2020
Ada Hamosh - updated : 03/01/2019
Paul J. Converse - updated : 6/11/2014
John A. Phillips, III - updated : 2/19/2002
Victor A. McKusick - updated : 4/6/2001
Paul J. Converse - updated : 7/20/2000
Jon B. Obray - updated : 6/29/1996
Creation Date:
Victor A. McKusick : 2/18/1988
carol : 03/04/2021
alopez : 02/13/2020
carol : 02/13/2020
carol : 02/12/2020
ckniffin : 02/10/2020
alopez : 03/01/2019
mgross : 07/14/2014
mcolton : 6/11/2014
alopez : 2/19/2002
alopez : 2/19/2002
carol : 10/2/2001
carol : 4/13/2001
mcapotos : 4/9/2001
terry : 4/6/2001
mgross : 7/20/2000
mgross : 7/20/2000
mgross : 7/20/2000
dkim : 9/11/1998
carol : 6/29/1996
supermim : 3/16/1992
supermim : 3/20/1990
ddp : 10/26/1989
marie : 3/25/1988
root : 2/18/1988

* 114190

CALCITONIN RECEPTOR-LIKE RECEPTOR; CALCRL


Alternative titles; symbols

CALCR; CRLR
CALCITONIN RECEPTOR-LIKE GENE
CALCITONIN GENE-RELATED PEPTIDE RECEPTOR; CGRPR


HGNC Approved Gene Symbol: CALCRL

Cytogenetic location: 2q32.1     Genomic coordinates (GRCh38): 2:187,341,964-187,448,252 (from NCBI)


Gene-Phenotype Relationships

Location Phenotype Phenotype
MIM number
Inheritance Phenotype
mapping key
2q32.1 ?Lymphatic malformation 8 618773 Autosomal recessive 3

TEXT

Description

The CALCRL gene encodes a G protein-coupled receptor (GPCR) that forms an active signaling complex for either adrenomedullin (ADM; 103275) or calcitonin gene-related peptide (CGRP; see 114130), depending on the receptor's interaction with RAMP proteins. Interaction of CALCRL with RAMP2 (605154) or RAMP3 (605155) leads to the formation of a receptor complex that binds ADM, whereas interaction with RAMP1 (605153) creates the active form of the CGRP-binding receptor. These 2 signaling pathways have different functions (summary by Mackie et al., 2018).


Cloning and Expression

Studies of the structure and expression of the calcitonin gene (CALCA; 114130) have demonstrated the generation of alternative mRNA species from a single gene in a tissue-specific manner. The mRNA species produced encode polyproteins cleaved by posttranslational events to yield either calcitonin (CT), the major gene product in the thyroid, or a predicted 37-amino acid amidated peptide, the calcitonin gene-related peptide (CGRP, or CGRP1). A second gene encoding a similar peptide (CGRP2, or CALCB; 114160) has been identified in man as well as in the rat. Receptors for CGRP have been located in the central nervous system by receptor-binding studies and visualized by optoradiography. Foord and Craig (1987) described the identification and purification of a receptor for CGRP in human term placenta.

By screening a cerebellum cDNA library with degenerate PCR primers corresponding to the rat calcitonin receptor-like receptor (Crlr) sequence, Fluhmann et al. (1995) isolated a cDNA encoding CGRPR, which they called CRLS (calcitonin receptor-like sequence). The deduced 461-amino acid CGRPR protein shares 91% amino acid identity with rat Crlr and 55% identity with CALCR. Northern blot analysis detected a major 5.2-kb CGRPR transcript and minor 7.3- and 3.4-kb CGRPR transcripts in heart, lung, and kidney; lower expression of the 5.2-kb transcript was detected in brain and placenta. Expression of CGRPR did not, however, confer binding of CT or CGRP, nor did it alter cyclic AMP accumulation in response to CT, CGRP, CGRP2, adrenomedullin (ADM; 103275), or amylin (IAPP; 147940).

Aiyar et al. (1996) cloned a cDNA encoding CGRPR, which shares significant peptide sequence homology with CALCR, a member of the G protein-coupled receptor superfamily. CGRPR is predominantly expressed in the lung and heart.


Gene Function

In a mammalian cell line without an endogenous receptor, McLatchie et al. (1998) observed increased intracellular cAMP levels in response to CGRP when CGRPR and receptor activity-modifying protein-1 (RAMP1; 605153) were expressed together, but not when they were expressed alone. Flow cytometric analysis showed that expression of CGRPR at the cell surface increases substantially when CGRPR is expressed with RAMP1. Likewise, surface expression of RAMP1 was shown to increase in cells also expressing CGRPR. SDS-PAGE analysis showed that binding of CGRP requires expression of both the 14-kD RAMP1 and the 58-kD CGRPR glycoprotein. The authors demonstrated that in the presence of RAMP1, CGRPR becomes a 66-kD terminally glycosylated protein. McLatchie et al. (1998) found that unlike RAMP1, RAMP2 (605154) and RAMP3 (605155) do not potentiate responses to CGRP but do transport the glycosylated 58-kD but not the 66-kD form of CGRPR to the cell surface. In frog oocytes and mammalian cells, coexpression of RAMP2 and CGRPR resulted in increased intracellular cAMP concentrations in response to ADM but not to CGRP, CT, or IAPP. SDS-PAGE analysis demonstrated that ADM binds to coexpressed RAMP2 and CGRPR.

By RT-PCR analysis, Kamitani et al. (1999) found coexpression of RAMP2 and CGRPR in endothelial and smooth muscle cells. They confirmed that the intracellular cAMP concentration increases in response to ADM in endothelial and smooth muscle cells coexpressing RAMP2 and CGRPR.

Foord and Marshall (1999) reviewed the roles of CGRPR and the RAMPs in mediating responses to peptides related to calcitonin. They stated that RAMPs transport CGRPR to the cell surface, define its pharmacology, and determine its glycosylation state. CALCRL is thus an ADM receptor when united with RAMP2, and a calcitonin gene-related peptide receptor when united with RAMP1.

McLatchie et al. (1998) demonstrated that a complex consisting of RAMP2 and CALCRL can function as an ADM receptor. To investigate whether ADM has implications as a pathophysiologic substance in pregnancy-induced hypertension, Makino et al. (2001) measured the changes of expression of RAMP2 and CALCRL in fetomaternal tissues in normotensive pregnant women and pregnancy-induced hypertensive women by Northern blot analysis. RAMP2 and CALCRL mRNA was significantly decreased in the umbilical artery and uterus of the patients with pregnancy-induced hypertension. On the other hand, RAMP2 mRNA was significantly increased in the fetal membrane of the patients with pregnancy-induced hypertension. In addition, there was a significant negative correlation between the RAMP2 mRNA levels in the umbilical artery and uterine muscle and blood pressure. However, there was no correlation between the mRNA level and blood pressure in fetal membrane and placenta, suggesting that there is no close relationship to the pathogenesis in pregnancy-induced hypertension. These findings suggested that the reduced expression of RAMP2 and CALCRL functioning as components of an adrenomedullin receptor in umbilical artery and uterus may have some role in pregnancy-induced hypertension.

Using monocyte-derived Langerhans cells (LCs) and a macrophage-tropic (see CCR5, 601373) human immunodeficiency virus (HIV)-1 (see 609423) molecular clone, Ganor et al. (2013) showed that CGRP acted via CRLR expressed on LCs and interfered with multiple steps of LC-mediated HIV-1 transmission. CGRP increased langerin (CD207; 604862) expression while decreasing that of selected integrins, such as CD1A (188370), CD11C (ITGAX; 151510), and DCSIGN (CD209; 604672). CGRP also activated NFKB (see 164011), resulting in decreased intracellular HIV-1, limited LC-T cell conjugate formation, and elevated secretion of the CCR5-binding chemokine CCL3 (182283). These mechanisms efficiently inhibited HIV-1 transfer from LCs to T cells. Compared with healthy humans and macaques, HIV-1 infection resulted in decreased plasma CGRP levels that could be reversed by highly active antiretroviral treatment (HAART, see 609423). Ganor et al. (2013) concluded that CGRP acts at molecular and cellular levels to limit mucosal HIV-1 transmission and that CRLR agonists may have therapeutic potential.


Gene Structure

Nakazawa et al. (2001) demonstrated that the CALCRL gene contains 15 exons and spans more then 103 kb of genomic DNA.


Mapping

Stumpf (2020) mapped the CALCRL gene to chromosome 2q32.1 based on an alignment of the CALCRL sequence (GenBank U17473.1) with the genomic sequence (GRCh38).


Biochemical Features

Cryoelectron Microscopy

Liang et al. (2018) reported the structure of the human CGRP (see 114130) receptor, a heterodimer of CALCRL and receptor activity-modifying protein-1 (RAMP1; 605153), in complex with CGRP and a Gs-protein heterotrimer at 3.3-angstrom global resolution, determined by cryoelectron microscopy. The RAMP1 transmembrane domain sits at the interface between transmembrane domains 3, 4, and 5 of CALCRL, and stabilizes CALCRL extracellular loop 2. RAMP1 makes only limited direct contact with CGRP, consistent with its function in allosteric modulation of CALCRL. Molecular dynamics simulations indicated that RAMP1 provides stability to the receptor complex, particularly in the positioning of the extracellular domain of CALCRL.


Molecular Genetics

In a 22-week-old male fetus, conceived of consanguineous parents, with hydrops fetalis due to lymphatic malformation (LMPHM8; 618773), Mackie et al. (2018) identified a homozygous in-frame deletion in the CALCRL gene (Val205del; 114190.0001). The mutation, which was found by exome sequencing and confirmed by Sanger sequencing, segregated with the disorder in the family. The variant was not found in the 1000 Genomes Project, Exome Sequencing Project, ExAC, or gnomAD databases. In the family, 3 female carriers of the mutation had reduced fertility associated with recurrent miscarriages; there were 8 total miscarriages among the 3 women, and 2 of the miscarriages were confirmed to be due to hydrops fetalis. In vitro functional expression studies in HEK293 cells showed that the mutant protein had reduced association with RAMP2, reduced translocation to the plasma membrane, and impaired signaling activity compared to wildtype. The findings were consistent with a specific loss-of-function effect targeting the CALCRL-RAMP2-ADM signaling pathway, which is essential for normal lymphangiogenesis.


Animal Model

Mackie et al. (2018) found that global deletion of the Calcrl gene in mice resulted in mid-gestation embryonic lethality with profound interstitial edema due to arrested lymphangiogenesis. The placentas from Calcrl-null mice showed marked interstitial edema within the labyrinth and enlarged junctional zone. Targeted deletion of the Calcrl gene in lymphatic endothelial cells also caused embryonic lethality with profound interstitial and subcutaneous edema. Histologic analysis showed small lymphatic vessels that were developmentally arrested, as well as dilated and malformed lymphatic capillaries compared to controls. The phenotype was similar to that observed in both Adm-null and Ramp2-null mice, confirming that the CALCRL-RAMP2-ADM signaling pathway is essential for normal lymphangiogenesis.


ALLELIC VARIANTS 1 Selected Example):

.0001   LYMPHATIC MALFORMATION 8 (1 family)

CALCRL, 3-BP DEL, NT614
SNP: rs1574226259, ClinVar: RCV001003344

In a 22-week-old male fetus, conceived of consanguineous Arab parents, with hydrops fetalis due to lymphatic malformation-8 (LMPHM8; 618773), Mackie et al. (2018) identified a homozygous 3-bp in-frame deletion (c.614_616del, NM_005795.5) in exon 9 of the CALCRL gene, resulting in deletion of the highly conserved residue Val205 (V205del) in extracellular loop 1. The mutation, which was found by exome sequencing and confirmed by Sanger sequencing, segregated with the disorder in the family. The variant was not found in the 1000 Genomes Project, Exome Sequencing Project, ExAC, or gnomAD databases. In the family, 3 female carriers of the mutation had reduced fertility associated with recurrent miscarriages; there were 8 total miscarriages among the 3 women, and 2 of the miscarriages were confirmed to be due to hydrops fetalis. In vitro functional expression studies in HEK293 cells showed that the mutant protein had reduced association with RAMP2 (605154), reduced translocation to the plasma membrane, and impaired signaling activity compared to wildtype. The findings were consistent with a specific loss-of-function effect targeting the CALCRL-RAMP2-ADM (103275) signaling pathway, which is essential for normal lymphangiogenesis. The fetus was also homozygous for a missense R349G variant in the ASAH1 gene (613468), which is associated with Farber lipogranulomatosis (FRBRL; 228000). FRBRL can sometimes present with antenatal hydrops fetalis; however, other clinical manifestations of FRBRL were not present in the fetus or in other nongenotyped families members.


REFERENCES

  1. Aiyar, N., Rand, K., Elshourbagy, N. A., Zeng, Z., Adamou, J. E., Bergsma, D. J., Li, Y. A cDNA encoding the calcitonin gene-related peptide type 1 receptor. J. Biol. Chem. 271: 11325-11329, 1996. [PubMed: 8626685] [Full Text: https://doi.org/10.1074/jbc.271.19.11325]

  2. Fluhmann, B., Muff, R., Hunziker, W., Fischer, J. A., Born, W. A human orphan calcitonin receptor-like structure. Biochem. Biophys. Res. Commun. 206: 341-347, 1995. [PubMed: 7818539] [Full Text: https://doi.org/10.1006/bbrc.1995.1047]

  3. Foord, S. M., Craig, R. K. Isolation and characterisation of a human calcitonin-gene-related-peptide receptor. Europ. J. Biochem. 170: 373-379, 1987. [PubMed: 2826160] [Full Text: https://doi.org/10.1111/j.1432-1033.1987.tb13710.x]

  4. Foord, S. M., Marshall, F. H. RAMPs: accessory proteins for seven transmembrane domain receptors. Trends Pharm. Sci. 20: 184-187, 1999. [PubMed: 10354609] [Full Text: https://doi.org/10.1016/s0165-6147(99)01347-4]

  5. Ganor, Y., Drillet-Dangeard, A.-S., Lopalco, L., Tudor, D., Tambussi, G., Delongchamps, N. B., Zerbib, M., Bomsel, M. Calcitonin gene-related peptide inhibits Langerhans cell-mediated HIV-1 transmission. J. Exp. Med. 210: 2161-2170, 2013. [PubMed: 24081951] [Full Text: https://doi.org/10.1084/jem.20122349]

  6. Kamitani, S., Asakawa, M., Shimekake, Y., Kuwasako, K., Nakahara, K., Sakata, T. The RAMP2/CRLR complex is a functional adrenomedullin receptor in human endothelial and vascular smooth muscle cells. FEBS Lett. 448: 111-114, 1999. [PubMed: 10217420] [Full Text: https://doi.org/10.1016/s0014-5793(99)00358-0]

  7. Liang, Y.-L., Khoshouei, M., Deganutti, G., Glukhova, A., Koole, C., Peat, T. S., Radjainia, M., Plitzko, J. M., Baumeister, W., Miller, L. J., Hay, D. L., Christopoulos, A., Reynolds, C. A., Wootten, D., Sexton, P. M. Cryo-EM structure of the active, Gs-protein complexed, human CGRP receptor. Nature 561: 492-497, 2018. [PubMed: 30209400] [Full Text: https://doi.org/10.1038/s41586-018-0535-y]

  8. Mackie, D. I., Al Mutairi, F., Davis, R. B., Kechele, D. L., Nielsen, N. R., Snyder, J. C., Caron, M. G., Kliman, H. J., Berg, J. S., Simms, J., Poyner, D. R., Caron, K. M. hCALCRL mutation causes autosomal recessive nonimmune hydrops fetalis with lymphatic dysplasia. J. Exp. Med. 215: 2339-2353, 2018. [PubMed: 30115739] [Full Text: https://doi.org/10.1084/jem.20180528]

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Contributors:
Cassandra L. Kniffin - updated : 02/10/2020
Ada Hamosh - updated : 03/01/2019
Paul J. Converse - updated : 6/11/2014
John A. Phillips, III - updated : 2/19/2002
Victor A. McKusick - updated : 4/6/2001
Paul J. Converse - updated : 7/20/2000
Jon B. Obray - updated : 6/29/1996

Creation Date:
Victor A. McKusick : 2/18/1988

Edit History:
carol : 03/04/2021
alopez : 02/13/2020
carol : 02/13/2020
carol : 02/12/2020
ckniffin : 02/10/2020
alopez : 03/01/2019
mgross : 07/14/2014
mcolton : 6/11/2014
alopez : 2/19/2002
alopez : 2/19/2002
carol : 10/2/2001
carol : 4/13/2001
mcapotos : 4/9/2001
terry : 4/6/2001
mgross : 7/20/2000
mgross : 7/20/2000
mgross : 7/20/2000
dkim : 9/11/1998
carol : 6/29/1996
supermim : 3/16/1992
supermim : 3/20/1990
ddp : 10/26/1989
marie : 3/25/1988
root : 2/18/1988