Using deletion-specific PCR, we found the same allele in 2 of 308 STGD subjects (0.32%), in 1 of 96 age-related macular degeneration (AMD) subjects (0.52%), and in 2 of 480 (0.2%) individuals with no known eye diseases, but it was absent in a control group consisting of 96 individuals over age 60 and with normal eye examinations.
Our studies on candidate genes of eye diseases in the Chinese population in Hong Kong include MYOC and TISR for primary open angle glaucoma, RHO and RP1 for retinitis pigmentosa, ABCA4 and APOE for age-related macular degeneration, RB1 for retinoblastoma, APC for familial adenomatous polyposis with congenital hypertrophy of retinal pigment epithelium, BIGH3/TGFBI for corneal dystrophies, PAX6 for aniridia and Reiger syndrome, CRYAA and CRYBB2 for cataracts, and mtDNA for Leber hereditary optic neuropathy.
Screening of increasingly large numbers of patients would help to determine whether this can be explained by ethnic differences, or is an indicator of extensive allelic heterogeneity of ABCR in STGD1 and other eye diseases.