Abstract
Purpose :
Age-related macular degeneration (AMD) susceptibility has a significant genetic component especially in people of European descent. The Armenian ethnogenesis dates back at least 3,000 years. This isolation was followed by a genetic bottleneck due to the Armenian genocide in the early 20th century. Considering the genetic events shaping the Armenian genome, we hypothesized that the genetic involvement in AMD of Armenians may be different than that other major continental populations. To our knowledge, this is the first reported evaluation of the genetic contribution of known AMD susceptibility variants in an Armenian population.
Methods :
We genotyped 128 Armenian subjects living in the Los Angeles California area for four SNPs and an indel on a genotyping panel to assess the relationship of these SNPs in AMD affecting people of Armenian descent. All subjects had a complete eye examination and photography and were classified according to the Clinical Age-Related Maculopathy Grading System. We calculated allele frequencies of the SNPs using all subjects and compared them to the frequencies in three major continental populations from the 1000 Genomes Project (Yoruba in Ibadan, Nigeria; Japanese in Tokyo, Japan/Han Chinese in Beijing, China; and Utah residents with ancestry from northern and western Europe). We performed a case/control association analysis comparing 58 Armenian subjects affected with advanced AMD (cases) to 15 unaffected Armenian subjects (controls) to determine if there is an association between these variants and AMD seen in Armenian subjects. IRB approval was obtained.
Results :
The genetic loci showed a high level of similarity in allele frequency to the European population and with the exception of one, had different frequencies compared with the African and Asian populations. The association analysis showed two SNPs in the complement factor H (CFH) gene and the indel in the Age-Related Maculopathy Susceptibility 2 (ARMS2) gene were significantly associated with AMD (p<0.01; Bonferroni adjusted p<0.05/5 genes).
Conclusions :
The allele frequencies between the Armenian samples and European samples were similar, and associations were found in the Armenian samples between AMD and the known AMD variants, including CFH and ARMS2. Additional analyses are needed in a larger sample size to fully understand the variants associated with the incidence of AMD in the Armenian population.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.