ABCA4 and Retinal dystrophy: The probands from families A, B, and E underwent testing for variants in the coding and flanking intronic regions of 105 or 176 known retinal dystrophy-causing genes, including a number of genes associated with macular drusen (ABCA4, NM_000350; CA4, NM_000717; CNGB3, NM_019098; EFEMP1, NM_001039348; PROM1, NM_006017; and TIMP3, NM_000362).