A locus for a human hereditary cataract is closely linked to the gamma-crystallin gene family.
Within the human gamma-crystallin gene cluster polymorphic Taq I sites are present. These give rise to three sets of allelic fragments from the gamma-crystallin genes. Together these restriction fragment length polymorphisms define eight possible haplotypes, three of which (Q, R, and S) were found in the Dutch and English population. A fourth haplotype (P) was detected within a family in which a hereditary Coppock-like cataract of the embryonic lens nucleus occurs in heterozygotes. Haplotype P was found only in family members who suffered from cataract, and all family members who suffered from cataract had haplotype P. The absolute correlation between the presence of haplotype P and cataract within this family shows that the gamma-crystallin gene cluster and the locus for the Coppock-like cataract are closely linked [logarithm of odds (lod) score of 7.58 at its maximum at phi = 0]. This linkage provides genetic evidence that the primary cause of a cataract in humans could possibly be a lesion in a crystallin gene.
D002386:Cataract / Q000235:genetics*; D002889:Chromosomes, Human, Pair 2; D003459:Crystallins / Q000235:genetics*; D004262:DNA Restriction Enzymes; D005260:Female; D005796:Genes; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D009693:Nucleic Acid Hybridization; D010375:Pedigree
D003459:Crystallins; D004262:DNA Restriction Enzymes