A third locu (GLC1D) for adult-onet primary open-angle glaucoma map to the 8q23 region Original Reearch Article

Purpoe: Two gene for adult-onet primary open-angle glaucoma have been mapped to chromoome 2cen-q13 and 3q21-q24. We tudied a family with adult-onet primary open-angle glaucoma in which the dieae did not map to thee two chromoomal region. Method: We acertained a four-generation family with adult-onet primary open-angle glaucoma in which the dieae tatu of individual wa objectively aigned uing defined criteria. Complete ophthalmologic examination, viual field teting, optic nerve head photograph, and venou blood ample were obtained. Family member were genotyped uing polymerae chain reaction amplification of microatellite polymorphic marker. Linkage analyi wa performed and lod core were calculated. Haplotype tranmiion data were analyzed. Reult: A total of 20 ubject in three ucceive generation agreed to participate in the tudy. Thi included ample from eight affected ubject, one glaucoma upect, one normal individual, and two poue in generation II and III, and an additional eight individual in generation IV. The phenotype in thi family appear to be variable, with onet of viual field lo in middle age, followed by modet elevation of intraocular preure and progreion of the dieae in older individual. Linkage wa etablihed with a group of DNA marker located in the 8q23 region. A lod core value of 3.61 wa obtained uing marker D81471. Three other marker from the ame region gave lod core value of over 3.0. Haplotype tranmiion data identified two recombination event that placed the gene in a 6.3-cM region flanked by D81830 and D8592. The dieae-bearing haplotype wa inherited by eight affected ubject and three glaucoma upect. Concluion: We preent evidence for a third adult-onet primary open-angle glaucoma locu (GLC1D) on chromoome 8q23. The genetic heterogeneity of adult-onet glaucoma i evident from the multiplicity of chromoomal loci aociated with thi dieae.