A major locus for autosomal recessive retinitis pigmentosa on 6q, determined by homozygosity mapping of chromosomal regions that contain gamma-aminobutyric acid-receptor clusters

A major locus for autosomal recessive retinitis pigmentosa (arRP) has been identified on 6q between markers D6S257 and D6S1644. It was established by homozygosity mapping in inbred families of chromosomal regions containing gamma-aminobutyric acid-receptor clusters. RP has extensive allelic and nonallelic genetic herogeneity. It appears that 10-20% of Spanish families affected by typical arRP may have linkage to the new locus. Of the cases of the disease in Spain, 47% present autosomal recessive inheritance.