AUTOSOMAL-DOMINANT CERULEAN CATARACT IS ASSOCIATED WITH A CHAIN TERMINATION MUTATION IN THE HUMAN BETA-CRYSTALLIN GENE CRYBB2

Congenital cataracts are a common major abnormality of the eye that fr equently cause blindness in infants, At least a third of all cases are familial; autosomal dominant congenital cataract (ADCC) appears to be the most common familial form in the Western world, Cerulean cataract s have peripheral bluish and white opacifications in concentric layers with occasional central lesions arranged radially, Although the opaci ties may be observed during fetal development and childhood, usually v isual acuity is only mildly reduced until adulthood, when lens extract ion is generally necessary, We have been studying a family (ADCC-1) wi th cerulean blue ADCC, in which the affected daughter of a first cousi n mating was presumed to be homozygous for the cataract gene, Recently , we mapped an ADCC gene in this family to a region of chromosome 22 c ontaining three beta-crystallin genes, Here we report that a chain-ter mination mutation in CRYBB2 is associated with ADCC in this family.