LINKAGE REFINEMENT LOCALIZES SORSBY FUNDUS DYSTROPHY BETWEEN MARKERS D22S275 AND D22S278

Sorsby fundus dystrophy is an autosomal dominant disorder which both c linically and histopathologically bears striking similarities to age r elated macular degeneration, one of the leading causes of blindness in the developed world. Recent studies have suggested a genetic localisa tion of the disease to chromosome 22q in a large genetic interval of a pproximately 25 cM. Independent genetic Linkage analysis in a six gene ration British pedigree confirms linkage to the chromosome 22q region. A maximum two point lod score of 7 . 09 with no recombination was obt ained with marker D22S280. Haplotype data positioned the disease betwe en loci D22S275 and D22S278, thus significantly reducing the region on chromosome 22q where the gene is located.