MedGen

Alagille syndrome (ALGS) is a multisystem disorder with a wide spectrum of clinical variability; this variability is seen even among individuals from the same family. The major clinical manifestations of ALGS are bile duct paucity on liver biopsy, cholestasis, congenital cardiac defects (primarily involving the pulmonary arteries), butterfly vertebrae, ophthalmologic abnormalities (most commonly posterior embryotoxon), and characteristic facial features. Renal abnormalities, growth failure, developmental delays, splenomegaly, and vascular abnormalities may also occur. [from GeneReviews]

The findings in X-linked chondrodysplasia punctata 2 (CDPX2) range from fetal demise with multiple malformations and severe growth retardation to much milder manifestations, including females with no recognizable physical abnormalities. At least 95% of live-born individuals with CDPX2 are female. Characteristic features include growth deficiency; distinctive craniofacial appearance; chondrodysplasia punctata (stippling of the epiphyses of the long bones, vertebrae, trachea, and distal ends of the ribs); often asymmetric rhizomelic shortening of limbs; scoliosis; linear or blotchy scaling ichthyosis in the newborn; later appearance of linear or whorled atrophic patches involving hair follicles (follicular atrophoderma); coarse hair with scarring alopecia; and cataracts. [from GeneReviews]

Baller-Gerold syndrome (BGS) can be suspected at birth in an infant with craniosynostosis and upper limb abnormality. The coronal suture is most commonly affected; the metopic, lambdoid, and sagittal sutures may also be involved alone or in combination. Upper limb abnormality can include a combination of thumb hypo- or aplasia and radial hypo- or aplasia and may be asymmetric. Malformation or absence of carpal or metacarpal bones has also been described. Skin lesions may appear anytime within the first few years after birth, typically beginning with erythema of the face and extremities and evolving into poikiloderma. Slow growth is apparent in infancy with eventual height and length typically at 4 SD below the mean. [from GeneReviews]

Phelan-McDermid syndrome is characterized by neonatal hypotonia, absent to severely delayed speech, developmental delay, and minor dysmorphic facial features. Most affected individuals have moderate to profound intellectual disability. Other features include large fleshy hands, dysplastic toenails, and decreased perspiration that results in a tendency to overheat. Normal stature and normal head size distinguishes Phelan-McDermid syndrome from other autosomal chromosome disorders. Behavior characteristics include mouthing or chewing non-food items, decreased perception of pain, and autism spectrum disorder or autistic-like affect and behavior. [from GeneReviews]

Axenfeld-Rieger syndrome is primarily an eye disorder, although it can also affect other parts of the body. This condition is characterized by abnormalities of the front part of the eye, an area known as the anterior segment. For example, the colored part of the eye (the iris), may be thin or poorly developed. The iris normally has a single central hole, called the pupil, through which light enters the eye. People with Axenfeld-Rieger syndrome often have a pupil that is off-center (corectopia) or extra holes in the iris that can look like multiple pupils (polycoria). This condition can also cause abnormalities of the cornea, which is the clear front covering of the eye.

About half of affected individuals develop glaucoma, a serious condition that increases pressure inside the eye. When glaucoma occurs with Axenfeld-Rieger syndrome, it most often develops in late childhood or adolescence, although it can occur as early as infancy. Glaucoma can cause vision loss or blindness.

Researchers have described at least three types of Axenfeld-Rieger syndrome. The types, which are numbered 1 through 3, are distinguished by their genetic cause.

The signs and symptoms of Axenfeld-Rieger syndrome can also affect other parts of the body. Many affected individuals have distinctive facial features such as widely spaced eyes (hypertelorism); a flattened mid-face with a broad, flat nasal bridge; and a prominent forehead. The condition is also associated with dental abnormalities including unusually small teeth (microdontia) or fewer than normal teeth (oligodontia). Some people with Axenfeld-Rieger syndrome have extra folds of skin around their belly button (redundant periumbilical skin). Other, less common features can include heart defects, the opening of the urethra on the underside of the penis (hypospadias), narrowing of the anus (anal stenosis), and abnormalities of the pituitary gland that can result in slow growth. [from MedlinePlus Genetics]

Combined pituitary hormone deficiency (CPHD) in man denotes impaired production of growth hormone (GH; 139250) and one or more of the other 5 anterior pituitary hormones. Mutations of the POU1F1 gene in the human and Pit1 in the mouse are responsible for pleiotropic deficiencies of GH, prolactin (PRL; 176760), and thyroid-stimulating hormone (TSH; see 188540), while the production of adrenocorticotrophic hormone (ACTH; see 176830), luteinizing hormone (LH; 152780), and follicle-stimulating hormone (FSH; 136530) are preserved (Wu et al., 1998). Some patients exhibit only GH deficiency, although approximately 50% of isolated GH deficiency progresses to CPHD (Gergics et al., 2021). In infancy severe growth deficiency from birth as well as distinctive facial features with prominent forehead, marked midfacial hypoplasia with depressed nasal bridge, deep-set eyes, and a short nose with anteverted nostrils and hypoplastic pituitary gland by MRI examination can be seen (Aarskog et al., 1997). Some cases present with severe mental retardation along with short stature (Radovick et al., 1992). Reviews Voss and Rosenfeld (1992) reviewed the development and differentiation of the 5 pituitary cell types: galactotropes, gonadotropes, corticotropes, thyrotropes, and somatotropes. As indicated by the mutations in PIT1 described later, combined pituitary hormone deficiency can have either autosomal dominant or autosomal recessive inheritance, depending on the part of the PIT1 molecule affected by the mutation. Some mutations have a dominant-negative effect. Genetic Heterogeneity of Combined Pituitary Hormone Deficiency CPHD2 (262600), associated with hypogonadism, is caused by mutation in the PROP1 gene (601538). CPHD3 (221750), which is associated with rigid cervical spine and variable sensorineural deafness, is caused by mutation in the LHX3 gene (600577). CPHD4 (262700) is caused by mutation in the LHX4 gene (602146). CPHD5 (see septooptic dysplasia, 182230) is caused by mutation in the HESX1 gene (601802). CPHD6 (613986) is caused by mutation in the OTX2 gene (600037). CPHD7 (618160) is caused by mutation in the RNPC3 gene (618016). [from OMIM]

FBXL4-related encephalomyopathic mitochondrial DNA (mtDNA) depletion syndrome is a multi-system disorder characterized primarily by congenital or early-onset lactic acidosis and growth failure, feeding difficulty, hypotonia, and developmental delay. Other neurologic manifestations can include seizures, movement disorders, ataxia, autonomic dysfunction, and stroke-like episodes. All affected individuals alive at the time they were reported (median age: 3.5 years) demonstrated significant developmental delay. Other findings can involve the heart (hypertrophic cardiomyopathy, congenital heart malformations, arrhythmias), liver (mildly elevated transaminases), eyes (cataract, strabismus, nystagmus, optic atrophy), hearing (sensorineural hearing loss), and bone marrow (neutropenia, lymphopenia). Survival varies; the median age of reported deaths was two years (range 2 days – 75 months), although surviving individuals as old as 36 years have been reported. To date FBXL4-related mtDNA depletion syndrome has been reported in 50 individuals. [from GeneReviews]

Desbuquois dysplasia (DBQD) is an autosomal recessive chondrodysplasia belonging to the multiple dislocation group and characterized by severe prenatal and postnatal growth retardation (stature less than -5 SD), joint laxity, short extremities, and progressive scoliosis. The main radiologic features are short long bones with metaphyseal splay, a 'Swedish key' appearance of the proximal femur (exaggerated trochanter), and advanced carpal and tarsal bone age with a delta phalanx (summary by Huber et al., 2009). Desbuquois dysplasia is clinically and radiographically heterogeneous, and had been classified into 2 types based on the presence (type 1) or absence (type 2) of characteristic hand anomalies, including an extra ossification center distal to the second metacarpal, delta phalanx, bifid distal thumb phalanx, and dislocation of the interphalangeal joints (Faivre et al., 2004). However, patients with and without these additional hand anomalies have been reported to have mutations in the same gene (see, e.g., CANT1); thus, these features are not distinctive criteria to predict the molecular basis of DBQD (Furuichi et al., 2011). In addition, Kim et al. (2010) described another milder variant of DBQD with almost normal outwardly appearing hands, but significant radiographic changes, including short metacarpals, elongated phalanges, and remarkably advanced carpal bone age. However, there is no accessory ossification center distal to the second metacarpal, and patients do not have thumb anomalies. Similar changes occur in the feet. These patients also tend to develop precocious osteoarthritis of the hand and spine with age. This phenotype is sometimes referred to as the 'Kim variant' of DBQD (Furuichi et al., 2011). Genetic Heterogeneity of Desbuquois Dysplasia DBQD2 (615777) is caused by mutation in the XYLT1 gene (608124) on chromosome 16p12. Two unrelated patients with immunodeficiency-23 (IMD23; 615816), due to mutation in the PGM3 gene (172100), were reported to have skeletal features reminiscent of DBQD. [from OMIM]

Prolidase deficiency is characterized by skin lesions (typically severe, chronic, recalcitrant, and painful skin ulcers of the lower extremities and telangiectasias of the face and hands), recurrent infections (particularly of the skin and respiratory tract), dysmorphic facial features, variable intellectual disability, and organomegaly (typically splenomegaly but occasionally associated with hepatomegaly) with elevated liver enzymes. Skeletal anomalies, chronic pulmonary disease, anemia, thrombocytopenia, hypergammaglobulinemia, and hypocomplementemia are observed in a minority of affected individuals. An association between prolidase deficiency and autoimmune conditions – particularly systemic lupus erythematosus (SLE) – has been described. [from GeneReviews]

EDAID2 is characterized by variable features of ectodermal dysplasia (e.g., hypo/anhidrosis, sparse hair, tooth anomalies) and various immunologic and infectious phenotypes of differing severity (summary by Boisson et al., 2017). Some patients may also have neutrophilia and autoinflammatory disease, such as liver disease (Tan et al., 2020). Mutations in the NFKBIA gene result in functional impairment of NFKB (see 164011), a master transcription factor required for normal activation of immune responses. Interruption of NFKB signaling results in decreased production of proinflammatory cytokines and certain interferons, rendering patients susceptible to infection (McDonald et al., 2007). For discussion of genetic heterogeneity of ectodermal dysplasia and immune deficiency, see 300291. [from OMIM]

Immunodeficiency-41 is an autosomal recessive complex disorder of immune dysregulation. Affected individuals present in infancy with recurrent viral, fungal, and bacterial infections, lymphadenopathy, and variable autoimmune features, such as autoimmune enteropathy and eczematous skin lesions. Immunologic studies show a defect in T-cell regulation (summary by Goudy et al., 2013). [from OMIM]

Spondyloepimetaphyseal dysplasia-short limb-abnormal calcification syndrome is a rare, genetic primary bone dysplasia disorder characterized by disproportionate short stature with shortening of upper and lower limbs, short and broad fingers with short hands, narrowed chest with rib abnormalities and pectus excavatum, abnormal chondral calcifications (incl. larynx, trachea and costal cartilages) and facial dysmorphism (frontal bossing, hypertelorism, prominent eyes, short flat nose, wide nostrils, high-arched palate, long philtrum). Platyspondyly (esp. of cervical spine) and abnormal epiphyses and metaphyses are observed on radiography. Atlantoaxial instability causing spinal compression and recurrent respiratory disease are potential complications that may result lethal. [from ORDO]

Autosomal recessive growth hormone insensitivity syndrome with immune dysregulation-1 (GHISID1) is a congenital disorder characterized by short stature due to insensitivity to growth hormone (GH1; 139250). Affected individuals usually have failure to thrive, delayed bone age, and delayed puberty associated with decreased serum IGF1 (147440), IGFBP3 (146732), and ALS (601489). Some patients may have dysmorphic features. Most, but not all, patients have features of immune dysregulation, including chronic pulmonary disease, interstitial pneumonitis, recurrent or severe infections, eczema, and autoimmune arthritis. The immune features are highly variable (summary by Kofoed et al., 2003; Vidarsdottir et al., 2006). See 262500 for a form of growth hormone insensitivity caused by mutation in the growth hormone receptor gene (GHR; 600946). [from OMIM]

Craniodiaphyseal dysplasia (CDD) is a severe bone dysplasia characterized by massive generalized hyperostosis and sclerosis, especially involving the skull and facial bones. Progressive bony encroachment upon cranial foramina leads to severe neurologic impairment in childhood (summary by Brueton and Winter, 1990). The sclerosis is so severe that the resulting facial distortion is referred to as 'leontiasis ossea' (leonine facies), and the bone deposition results in progressive stenosis of craniofacial foramina (summary by Kim et al., 2011). [from OMIM]

Congenital disorder of glycosylation type IIw (CDG2W) is an autosomal dominant metabolic disorder characterized by liver dysfunction, coagulation deficiencies, and profound abnormalities in N-glycosylation of serum specific proteins. All reported patients carry the same mutation (602671.0017) (summary by Ng et al., 2021). For an overview of congenital disorders of glycosylation, see CDG1A (212065) and CDG2A (212066). [from OMIM]

Developmental and epileptic encephalopathy-81 (DEE81) is an autosomal recessive neurodevelopmental disorder typically characterized by onset of severe refractory seizures soon after birth or in the first months of life. Affected individuals show little developmental progress with no eye contact and no motor or cognitive development. Other features may include facial dysmorphism, such as hypotonic facies and epicanthal folds, as well as sensorineural hearing loss and peripheral neuropathy. Brain imaging shows cerebral atrophy, impaired myelination, thin corpus callosum, and progressive leukoencephalopathy (summary by Esposito et al., 2019; Maddirevula et al., 2019). For a discussion of genetic heterogeneity of DEE, see 308350. [from OMIM]

Autosomal recessive cutis laxa type IIC (ARCL2C) is characterized by generalized skin wrinkling with sparse subcutaneous fat and dysmorphic progeroid facial features. Most patients also exhibit severe hypotonia as well as cardiovascular involvement (summary by Van Damme et al., 2017). For a general phenotypic description and a discussion of genetic heterogeneity of autosomal recessive cutis laxa, see ARCL1A (219100). [from OMIM]

Some ectodermal dysplasias are here classified as congenital disorders characterized by abnormal development in 2 or more ectodermal structures (hair, nails, teeth, and sweat glands) without other systemic findings. Hypohidrotic, or anhidrotic, ectodermal dysplasia (HED/EDA) is characterized by a triad of signs comprising sparse hair (hypotrichosis), abnormal or missing teeth (anodontia or hypodontia), and inability to sweat (anhidrosis or hypohidrosis). Typical clinical manifestations also include dryness of the skin, eyes, airways, and mucous membranes presumably due to the defective development of several exocrine glands. Hypohidrotic ectodermal dysplasia can be associated with dysmorphic features (forehead bumps, rings under the eyes, everted nose, and prominent lips) and occasionally with absent nipples (summary by Cluzeau et al., 2011). [from OMIM]

SHRF is an autosomal recessive disorder characterized by short stature, brachydactyly, dysmorphic facial features, hearing loss, and visual impairment. Onset of the hearing and visual abnormalities, including retinitis pigmentosa, varies from birth to the second decade. Patients have mild intellectual disability and mild cerebellar atrophy with myelination defects on brain imaging (summary by Di Donato et al., 2016). [from OMIM]

Granulomatosis with polyangiitis, formerly termed Wegener granulomatosis, is a systemic disease with a complex genetic background. It is characterized by necrotizing granulomatous inflammation of the upper and lower respiratory tract, glomerulonephritis, vasculitis, and the presence of antineutrophil cytoplasmatic autoantibodies (ANCAs) in patient sera. These ANCAs are antibodies to a defined target antigen, proteinase-3 (PR3, PRTN3; 177020), which is present within primary azurophil granules of neutrophils (PMNs) and lysozymes of monocytes. On cytokine priming of PMNs, PR3 translocates to the cell surface, where PR3-ANCAs can interact with their antigens and activate PMNs. PMNs from patients with active GPA express PR3 on their surface, produce respiratory burst, and release proteolytic enzymes after activation with PR3-ANCAs. The consequence is a self-sustaining inflammatory process (Jagiello et al., 2004). [from OMIM]