A PHOTORECEPTOR CELL-SPECIFIC ATP-BINDING TRANSPORTER GENE (ABCR) IS MUTATED IN RECESSIVE STARGARDT MACULAR DYSTROPHY

Stargardt disease (STGD, also known as fundus flavimaculatus; FFM) is an autosomal recessive retinal disorder characterized by a juvenile-on set macular dystrophy, alterations of the peripheral retina, and subre tinal deposition of lipofuscin-like material. A gene encoding an ATP-b inding cassette (ABC) transporter was mapped to the 2-cM (centiMorgan) interval at 1p13-p21 previously shown by linkage analysis to harbour the STGD gene. This gene, ABCR, is expressed exclusively and at high l evels in the retina, in rod but not cone photoreceptors, as detected b y in situ hybridization. Mutational analysis of ABCR in STGD families revealed a total of 19 different mutations including homozygous mutati ons in two families with consanguineous parentage. These data indicate that ABCR is the causal gene of STGD/FFM.