zonular opacities

Cataracts, Congenital Zonular With Sutural Opacities

Clinical Characteristics
Ocular Features: 

This form of heritable congenital cataracts consists of both zonular and sutural opacities.  Both anterior and posterior Y sutures are involved with fine dots.  The zonular opacities consist of a hazy cloud of fine, minute dots so  vision is usually good as the opacities are not dense.  The dots are arranged in a lamellar or clumped pattern with the fetal nucleus most consistently involved.  There is often a faint cloud of white dots at the suture ends.  Most of the phenotypic variation is in the density of the opacities rather than their location.  Older individuals often develop nuclear and posterior subcapsular sclerosis.

Systemic Features: 

No systemic abnormalities have been reported.

Genetics

This is an autosomal dominant disorder.  A mutation in the CRYBA1 gene (17q11-q12) segregates with the phenotype.

A form of congenital cerulean cataract (115660) also maps to the long arm of chromosome 17 but in the q24 region.

Another type of autosomal dominant congenital sutural cataract (607133) has been reported in a single 5 generation Indian family in which a mutation in CRYBB2 on chromosome 22 was associated.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Cataract surgery can be considered if vision is significantly impacted.

References
Article Title: 

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.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Cataract surgery may be indicated.

References
Article Title: 
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