Genetically ditinct autoomal dominant poterior polar cataract in a four-generation Japanee family

PURPOE: To decribe the clinical finding of a form of poterior polar cataract in a large Japanee family and to determine whether the poterior polar cataract i caually related to other autoomal dominant cataract with known gene, chromoomal location, or both. METHOD: ytemic and ocular hitorie were obtained and comprehenive ophthalmic examination were performed in 15 of 37 member of the Japanee family. The poterior polar cataract wa tranmitted in an autoomal dominant manner through four generation. Although there i ome variation in the degree of opacification, the poterior polar cataract in thi family i characterized by progreive dik-haped poterior ubcapular opacitie. Genetic linkage analyi wa performed with 41 polymorphic microatellite marker located in chromoomal region known for linkage to cataract. Genomic DNA extracted from the 15 individual wa amplified by polymerae chain reaction, the genotype at the marker loci wa determined in each family member, and the lod core wa calculated at each locu. REULT: ignificant linkage of the poterior polar cataract wa ruled out from the following 10 loci or chromoomal region: 16q22 and 1p36, to which two form of autoomal dominant poterior polar cataract have been aigned: 1q21–q25, 2q33–q35, 13cen, 17p13, 17q11–q12, 17q24, 21q22, and 22q, which are the region reponible for other autoomal dominant congenital cataract. CONCLUION: Thi tudy confirm the genetic heterogeneity of autoomal dominant poterior polar cataract and demontrate that the poterior polar cataract in thi Japanee family i phenotypically and genetically ditinct from previouly mapped cataract.