A GENE FOR LATE-ONSET FUNDUS FLAVIMACULATUS WITH MACULAR DYSTROPHY MAPS TO CHROMOSOME 1P13

Fundus flavimaculatus with macular dystrophy is an autosomal recessive disease responsible for a progressive loss of visual acuity in adulth ood, with pigmentary changes of the macula, perimacular flecks, and at rophy of the retinal pigmentary epithelium. Since this condition share s several clinical features with Stargardt disease, which has been map ped to chromosome 1p21-p13, we tested the disease for linkage to chrom osome 1p. We report here the mapping of the disease locus to chromosom e 1p13-p21, in the genetic interval defined by loci D1S435 and D1S415, in four multiplex families (maximum lod score 4.79 at recombination f raction 0 for probe AFM217zb2 at locus D1S435). Thus, despite differen ces in the age at onset, clinical course, and severity, fundus flavima culatus with macular dystrophy and Stargardt disease are probably alle lic disorders. This result supports the view that allelic mutations pr oduce a continuum of macular dystrophies, with onset in early childhoo d to late adulthood.