Genetics of age-related macular degeneration

AMD is likely to be a complex genetic disease as shown by population, family, and twin segregation and aggregation studies. The first genetic locus for AMD was designated ARMD1 and identified by conventional linkage analysis using a large multigenerational family with AMD. Another genetic study using sibling pairs and a nonparametric linkage approach confirmed this locus as a potential site for a gene that causes AMD. This second study identified additional chromosomal loci that are likely to contain genes for AMD. Candidate gene analysis has implicated the Stargardt disease gene designated ABCA4(ABCR) as a cause of AMD; however, this finding remains controversial. Contradictory reports have been published that refute the association between AMD and the Stargardt disease gene. Extensive analyses of genes that cause early-onset macular degenerations have not yet identified any other association between these diseases and AMD. There have been several reports that the apolipoprotein E gene may play an important role in determining the risk of developing AMD.