Abstract
Purpose :
To ascertain the prevalence of age related macular degeneration (AMD) and to examine the role of a polymorphism in the candidate gene COL8A1 (collagen, type VIII, alpha 1) in two Sardinian genetic isolates.
Methods :
An epidemiologic survey was conducted in two Ogliastra villages, in central eastern Sardinia, Baunei and Urzulei (n=2593). Detailed questionaries were administered to obtain demographic information, smoking history, alcohol intake, sunlight exposure, medical history, medication use and diet. Participants underwent a complete eye examination including OCT. We then evaluated those subjects over 50 years old (n=1148) for the clinical signs of AMD, that were assessed on colour fundus photographs using a modification of the Wisconsin Age-related Maculopathy Grading System protocol. Blood samples were taken for biochemical determinations and DNA extraction. Subjects were genotyped using Illumina Human Exome BeadChip array. A case control test for samples with related individuals was performed on rs139380413 SNP (COL8A1 gene) in 169 subjects.
Results :
AMD lesions were classified as dry (n=106), wet (n=11) and mixed (n=4). Overall prevalence of AMD was 10.5%, with no significant gender differences. We reconstructed the pedigrees of all diseased subjects and observed that those affected by the dry form of AMD (dAMD) better clustered in families. The case control test for related individuals was performed on 73 cases with dAMD and 96 controls, and resulted in a significant association of the rs139380413 SNP with dAMD (p=0.037). We observed a frequency of the A allele of 6.8% in cases and 2.6% in controls.
Conclusions :
The rs139380413(A) allele is reported here for first time to be differently distributed between dAMD patients and controls. COL8A1 rs139380413 polymorphism is associated with dAMD, suggesting that this gene may be a susceptibility gene locus for dAMD in Sardinian population.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.