Associations of the G1961E and D2177N variants in ABCA4 and the risk of age-related macular degeneration

• ABCA4 alleles were associated with age-related macular degeneration (AMD) risk.
• A more significant relationship in D2177N mutation with AMD was found in Americans.
• Neither the G1961E nor D2177N variant was detected in Asians.

ObjectiveThe aim of this study was to identify the relationship between G1961E and D2177N variants in the ABCA4 gene with AMD susceptibility.Design and methodsAll eligible studies published up to October 2014 were obtained from MEDLINE, EMBASE, and ISI Web of Science. The pooled odds ratio (OR) with 95% confidence intervals (CIs) was calculated to evaluate the strength of this association.ResultsTwenty-four studies enrolling 4580 AMD cases and 5180 controls were identified. Both G1961E (OR = 3.22, 95% CI: 1.74–5.95) and D2177N (OR = 2.36, 95% CI: 1.41–3.93) variations showed significant associations with increased risk of AMD. In addition, a more significant relationship in the D2177N mutation with increased risk for AMD was found in Americans (OR = 4.31, 95% CI: 1.90–9.73), while no association was demonstrated in Europeans. For Asians, no carriers of the risk factor A allele in either variant were detected in any of AMD patients and control subjects.ConclusionsSignificant evidence was found for a relationship between the G1961E and D2177N variants in ABCA4 with increased susceptibility to AMD, specifically for Americans. However, large-scale studies are still required to further validate these findings in different ethnicities.