A new locus for autosomal recessive Retinitis Pigmentosa (arRP) on chromosome 3p26–25.

Abstract

Abstract: : Purpose To determine whether the known arRP loci account for a significant proportion of cases and to test for possible founder mutations causing recessive RP within the Pakistani communities of the UK and Northern Pakistan. Methods We carried out a whole genome linkage search in a cohort of ten multiplex and ten simplex consanguineous RP families. Six multiplex families were from the Mirpur district of Northern Pakistan. The remaining families and cases were from the UK Pakistani community. 410 STR markers from the Marshfield version 10 marker panel were genotyped in a total of 99 DNA samples from these families. ResultsAnalysis of this data with the linkage programme GENEHUNTER, allowing for locus heterogeneity, detected linkage with a lod score of 3 to marker D3S4545 on chromosome 3p. Further markers in this region were typed, giving a maximum multipoint lod score of 5.3 at marker D3S1304. No single family gave a lod score above three, but two multiplex UK families gave multipoint lod scores of 2.65 and 2.15, and a further five simplex cases are homozygous for multiple markers in this vicinity. Haplotype analysis in the two best linked families gives a genetic refinement between markers D3S1560 and D3S4545. Conclusions These data provide evidence for a new locus for arRP, in an interval of 4.3mb or 11cM on chromosome 3p26.2–25.3.

Keywords: retinal degenerations: hereditary • linkage analysis • genetics