Cataracts, Coppock-Like

Clinical Characteristics
Ocular Features: 

Coppock-like cataracts consist of bilateral progressive opacities of the embryonic lens nucleus.  They are characterized by a pulverulent opacification with a gray disc appearance associated with variable zonular opacities.  Visual symptoms often begin during adolescence and some patients require cataract surgery by the 5th decade of life. 

Systemic Features: 

There is no systemic disease associated with this type of cataract.  

Genetics

CCL cataracts are embryonic in origin, developing during the time when gamma-crystallin genes are active.  The gamma E-crystallin gene is a pseudogene and the mutation in its promoter reactivates its activity 10-fold.  It is postulated that overexpression of the gamma-crystallin fragment is responsible for the nuclear opacification.

Mutations in at least 3 genes have been associated with this type of cataract.  In some families the mutations are in the CRYGC gene (2q33-q35), and in others mutations in CRYBB2 (22q11.2-q12.2) seem to be responsible.  It is of interest that one form of congenital cerulean cataract, CCA3 (608983), found in a single family, results in mutations in CRYGD also located at 22q11.2-q12.2.  A five-generation Chinese family has been reported in which mutations in GJA3 (13q12.11) was associated with this type of lens opacity.

Other forms of autosomal dominantly inherited, congenital, progressive lens opacities include congenital cerulean (115660, 601547, 608983, 610202), Volkmann type (115665), lamellar (116800), and congenital posterior polar (116600) cataracts. Due to clinical heterogeneity, it is not always possible to classify specific families based on the appearance and natural history of the lens opacities alone.

Treatment
Treatment Options: 

Cataract surgery may be indicated.

References
Article Title: 

References

Gill D, Klose R, Munier FL, McFadden M, Priston M, Billingsley G, Ducrey N, Schorderet DF, H?(c)on E. Genetic heterogeneity of the Coppock-like cataract: a mutation in CRYBB2 on chromosome 22q11.2. Invest Ophthalmol Vis Sci. 2000 Jan;41(1):159-65.

PubMedID: 10634616

Brakenhoff RH, Henskens HA, van Rossum MW, Lubsen NH, Schoenmakers JG. Activation of the gamma E-crystallin pseudogene in the human hereditary Coppock-like cataract. Hum Mol Genet. 1994 Feb;3(2):279-83.

PubMedID: 8004095

Zhang L, Qu X, Su S, Guan L, Liu P. A novel mutation in GJA3 associated with congenital Coppock-like cataract in a large Chinese family. Mol Vis. 2012;18:2114-8.

PubMedID: 22876138