OMIM ID:
Vitreoretinopathy with Epiphyseal Dysplasia
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
The axial length is relatively normal in this disorder. The vitreous is described as highly disorganized but without membranes or the usual lamellar array. Lattice degeneration may be seen in all quadrants and rhegmatogenous retinal detachments are a lifelong risk, occurring as early as the second decade of life.
Systemic Features
This is a unique type of type II collagenopathy with joint and vitreous disease. Patients do not have the short stature or midface hypoplasia of Kniest dysplasia (156550) nor the optically empty vitreous of Stickler syndrome type I (609508, 108300) caused by mutations in the same gene. The arthropathy secondary to the epiphyseal dysplasia is mainly in the fingers but some patients do have premature degenerative hip disease. The fingers are described as ‘stubby’.
Genetics
Inheritance
Mutations in the COL2A1 gene, important for collagen formation, cause various autosomal dominant skeletal dysplasias and some [Stickler type I (609508, 108300) syndrome and Kniest dysplasia (156550)] including this one exhibit vitreoretinopathy. This is an example of allelic heterogeneity in which various alleles of COL2A1 cause clinically distinguishable phenotypes of bone and ocular disease. Collagen II is found in cartilage and vitreous perhaps accounting for the associated clinical findings.
Pedigree
Autosomal dominant
Autosomal dominant disorders require only one mutation for the disease to be expressed. Since an affected parent has two chromosomes, only one of which has the mutant gene, parents can expect that half (50%) of their children will receive that one and inherit the disease. It is common for individuals that inherit the mutation, however, to not have evidence of the disease (nonpenetrance).
Autosomal dominant inheritance leads to a vertical pattern of transmission