MedGen

A heterogeneous group of disorders associated with walking and growth disturbances that become evident during the second year of life. Characteristics are platyspondyly (flattened vertebrae) and marked hip and knee metaphyseal lesions. The different forms of spondylometaphyseal dysplasia are distinguished by the localisation and severity of involvement of the affected metaphyses. [from SNOMEDCT_US]

Avascular necrosis of the femoral head (ANFH) is a debilitating disease that usually leads to destruction of the hip joint in the third to fifth decade of life. The disorder is characterized by progressive pain in the groin, mechanical failure of the subchondral bone, and degeneration of the hip joint. Nearly one-half of patients require hip replacement before 40 years of age. ANFH represents a specific form of the broader disease category of osteonecrosis (summary by Mont and Hungerford, 1995). Genetic Heterogeneity of Primary Avascular Necrosis of the Femoral Head ANFH2 is caused by mutation in the TRPV4 gene (605427) on chromosome 12q24. Mutation in COL2A1 has also been found in Legg-Calves-Perthes disease (LCPD; 150600), a form of ANFH in growing children. [from OMIM]

Spondyloepiphyseal dysplasia with accumulation of glycoprotein in chondrocytes has been designated the 'Stanescu type.' Clinical hallmarks include progressive joint contracture with premature degenerative joint disease, particularly in the knee, hip, and finger joints. Interphalangeal joints of the hands are swollen due to osseous distention of the metaphyseal ends of the phalanges. Affected individuals may be relatively tall despite the presence of a short trunk. Radiologically, there is generalized platyspondyly with mild modification of the endplates, hypoplastic pelvis, epiphyseal flattening with metaphyseal splaying of the long bones, and enlarged phalangeal epimetaphyses of the hands. In addition, the proximal femora are characteristically broad and elongated with striking coxa valga (summary by Nishimura et al., 1998). [from OMIM]

Stickler syndrome is a connective tissue disorder that can include ocular findings of myopia, cataract, and retinal detachment; hearing loss that is both conductive and sensorineural; midfacial underdevelopment and cleft palate (either alone or as part of the Robin sequence); and mild spondyloepiphyseal dysplasia and/or precocious arthritis. Variable phenotypic expression of Stickler syndrome occurs both within and among families; interfamilial variability is in part explained by locus and allelic heterogeneity. [from GeneReviews]

The term 'not provided' is registered in MedGen to support identification of submissions to ClinVar for which no condition was named when assessing the variant. 'not provided' differs from 'not specified', which is used when a variant is asserted to be benign, likely benign, or of uncertain significance for conditions that have not been specified. [from NCBI]

Mild spondyloepiphyseal dysplasia due to COL2A1 mutation with early-onset osteoarthritis is a type 2 collagen-related bone disorder characterized by precocious, generalized osteoarthritis (with onset as early as childhood) and mild, dysplastic spinal changes (flattening of vertebrae, irregular endplates and wedge-shaped deformities) resulting in a mildly short trunk. [from ORDO]

Spondyloepiphyseal dysplasia congenita (SEDC) is an autosomal dominant chondrodysplasia characterized by disproportionate short stature (short trunk), abnormal epiphyses, and flattened vertebral bodies. Skeletal features are manifested at birth and evolve with time. Other features include myopia and/or retinal degeneration with retinal detachment and cleft palate (summary by Anderson et al., 1990). [from OMIM]

A rare primary bone dysplasia characterized by the association of multiple epiphyseal dysplasia, visual impairment (with early-onset progressive myopia, retinal thinning, and cataracts), and conductive hearing loss. Patients are of short stature and present brachydactyly, genu valgus deformity, and joint pain. [from ORDO]

The Torrance type of platyspondylic lethal skeletal dysplasia (PLSDT) is an autosomal dominant disorder characterized by varying platyspondyly, short ribs with anterior cupping, hypoplasia of the lower ilia with broad ischial and pubic bones, and shortening of the tubular bones with splayed and cupped metaphyses. Histology of the growth plate typically shows focal hypercellularity with slightly enlarged chondrocytes in the resting cartilage and relatively well-preserved columnar formation and ossification at the chondroosseous junction. Though generally lethal in the perinatal period, longer survival has been reported (summary by Zankl et al., 2005). [from OMIM]

Czech dysplasia is an autosomal dominant skeletal dysplasia characterized by early-onset, progressive pseudorheumatoid arthritis, platyspondyly, and short third and fourth toes (Marik et al., 2004; Kozlowski et al., 2004). [from OMIM]

A rare hereditary non-syndromic form of vitreoretinopathy with characteristics of retinal tears due to abnormal vitreous and commonly present refractive errors. No other signs or symptoms of Stickler syndrome are present. Can be caused by mutation in the COL2A1 gene. [from SNOMEDCT_US]

Spondyloperipheral dysplasia is a disorder that impairs bone growth. This condition is characterized by flattened bones of the spine (platyspondyly) and unusually short fingers and toes (brachydactyly), with the exception of the first (big) toes. Other skeletal abnormalities associated with spondyloperipheral dysplasia include short stature, shortened long bones of the arms and legs, exaggerated curvature of the lower back (lordosis), and an inward- and upward-turning foot (clubfoot). Additionally, some affected individuals have nearsightedness (myopia), hearing loss, and intellectual disability. [from MedlinePlus Genetics]

Kniest dysplasia is characterized by skeletal and craniofacial anomalies. Skeletal anomalies include disproportionate dwarfism, a short trunk and small pelvis, kyphoscoliosis, short limbs, and prominent joints and premature osteoarthritis that restrict movement. Craniofacial manifestations include midface hypoplasia, cleft palate, early-onset myopia, retinal detachment, and hearing loss. The phenotype is severe in some patients and mild in others. There are distinct radiographic changes including coronal clefts of vertebrae and dumbbell-shaped femora. The chondrooseous morphology is pathognomonic with perilacunar 'foaminess' and sparse, aggregated collagen fibrils resulting in an interterritorial matrix with a 'Swiss-cheese' appearance (summary by Wilkin et al., 1999). [from OMIM]

Achondrogenesis type II (ACG2) is characterized by severe micromelic dwarfism with small chest and prominent abdomen, incomplete ossification of the vertebral bodies, and disorganization of the costochondral junction. ACG2 is an autosomal dominant trait occurring mostly as new mutations. However, somatic and germline mosaicism have been reported (summary by Comstock et al., 2010). [from OMIM]

Legg-Calve-Perthes disease (LCPD) is characterized by loss of circulation to the femoral head, resulting in avascular necrosis in a growing child. Clinical pictures of the disease vary, depending on the phase of disease progression through ischemia, revascularization, fracture and collapse, and repair and remodeling of the bone. The disease occurs more frequently in boys, and most patients tend to be shorter than their peers. Both familial and isolated cases of LCPD have been reported (summary by Chen et al., 2004). [from OMIM]