Familial cases with age-related macular degeneration.

The pathogenesis of age-related macular degeneration (AMD) remains unknown. Genetic and environmental factors are thought to be associated with AMD. Although some studies have reported familial cases of AMD in the United States, as far as we know, familial cases of AMD have rarely been reported in Japan. We describe three families with two members of each family affected with AMD and one family with three affected members. In one family, two siblings were affected with AMD with choroidal neovascularization and two other siblings had retinal pigment epithelial abnormalities or drusen of the maculas, suggesting the heterogeneity of the maculas in the family. However, the other families did not show such heterogeneity of the fundus. Among the four families, six of nine affected individuals had a smoking habit, a risk factor for AMD. These findings suggest that the development and progression of AMD might be associated with genetic factors and environmental factors.