A PROGRESSIVE EARLY-ONSET CATARACT GENE MAPS TO HUMAN-CHROMOSOME 17Q24

Cerulean cataract is an autosomal dominant, early onset, progressive cataract characterized by blue or white opacifications in the nucleus and cortex of the lens. A large four-generation pedigree in which cerulean cataract segregates was studied for linkage analysis. A genome wide search was undertaken after the plausible candidate genes were excluded and the cerulean cataract phenotype was mapped to chromosome 17q24. The three markers closest to the disease gene are D17S802 (Z(theta)=9.46 at (theta)=0.085), D17S836 (Z(theta)=5.26 at (theta)=0.031) and AFMa238yb5 (Z(theta)=7.11 at (theta)=0.032). Multipoint linkage analyses yielded a maximum lod score of Z(theta)=13.71, placing the cerulean cataract gene between D17S802 and D17S836 at (theta)=0.048 and (theta)=0.013, respectively.