OMIM ID:
Cataracts, Congenital Zonular With Sutural Opacities
Alternate Names
Defective Genes
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
Inheritance
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
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