Primary Open Angle Glaucoma (POAG) is the leading cause of blindness among African Americans living in the United States. Within this patient population, it has a prevalence that is 4-6 times greater, clinically more severe, and more likely to lead to blindness than in white Americans. The objective of this research is to determine the genetic basis of this complex inherited disease. With this vital information, future methods of diagnosis, treatment and possible prevention will be elucidated. POAG is highly prevalent and is a leading cause of blindness in West Africa. A large portion of the African American population living in the United States has its origins in West Africa. The study of genetics of POAG in the West African population offers several advantages to similar studies being conducted in the United States. Glaucoma is highly prevalent in West Africa and POAG is the dominant form. Families are larger in West Africa are mobile. These qualities greatly assist identifying and then locating families and family members that meet study criteria. Disease phenotype is generally more severe, at least in part due to shortages in health care delivery. Therefore, families with multiple affected members are more common, a critical element for any genetic study. Finally, the populations on West Africa are more homogeneous than similar populations in the U.S. and elsewhere. There has been very little population emigration to Ghana or West Africa thus resulting in reduced genetic admixture. Genetic admixture is very common in the U.S. and elsewhere. This is very important since greater genetic homogeneity increases the power to detect and identify genetic sources of inherited diseases.
The specific aims of this study are to 1) screen glaucoma patient populations in Ghana, West Africa and identify 150 discordant sib pairs with POAG and 2) create a West African POAG clinical and DNA association dataset to evaluate current and future candidate loci for POAG. Candidate genes within regions that demonstrate association will be screened using SNP and gene sequencing strategies. The clinical and genetic dataset created by proposal will be invaluable for future investigations of glaucoma in this population. This dataset can also serve as a foundation for genetic linkage dataset for genome-wide screen to identify new candidate genes and loci in this important population.
