Linkage of Chinese Families With Autosomal Recessive Retinitis Pigmentosa to the RP25 Locus

Abstract

Purpose: : To identify the disease locus in Chinese families with autosomal recessive retinitis pigmentosa (arRP)

Methods: : Sixteen individuals including seven affected from three non–consanguineous Chinese families participated in the study. A total of 130 single nucleotide polymorphisms (SNPs) and microsatellite markers corresponding to 22 arRP loci were used for genotyping. Mutation screening of CERKL, SAG, LRAT, and MERTK genes was performed for the families that could not be excluded by using SNPs or microsatellite markers.

Results: : Twenty one loci were excluded as the disease loci, only the RP25 locus could not be excluded from the studied families. By increasing the density of markers in the interval and combining the data from the studied families a maximum two point LOD score of 2.48 was obtained for the marker D6S402 at &#952 = 0. Recombination events defined a critical interval spanning 9.9 cM at the long arm of chromosome 6 between markers D6S257 and D6S460.

Conclusions: : This is the first report of a genetic study in Chinese population with arRP. RP25 could be a major locus for recessive RP as linkage to this locus was reported previously in two different ethnic groups. Genetic refinement of the interval by recruiting additional families together with screening candidate genes in the region is underway.

Keywords: genetics • linkage analysis • retina