chondrocalcin

Vitreoretinopathy with Epiphyseal Dysplasia

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

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
Treatment
Treatment Options: 

Retinal detachments, of course, require repair.  The lifelong risk of detachments requires monitoring.

References
Article Title: 

The phenotypic spectrum of COL2A1 mutations

Nishimura G, Haga N, Kitoh H, Tanaka Y, Sonoda T, Kitamura M, Shirahama S, Itoh T, Nakashima E, Ohashi H, Ikegawa S. The phenotypic spectrum of COL2A1 mutations. Hum Mutat. 2005 Jul;26(1):36-43.

PubMed ID: 
15895462
Subscribe to RSS - chondrocalcin