Abstract
Purpose :
The Pakistan Punjab population has been a rich source for identifying genes causing or contributing to autosomal recessive retinal degenerations (arRD). This study was carried out to delineate the genetic architecture in the Pakistani population.
Methods :
The genetic origin of arRD in a total of 144 families selected only for having consanguineous marriages and multiple members affected with arRD were examined. Of these, causative mutations had been identified in 65 families while only the locus had been identified for an additional 12. The remaining 67 families were subjected to homozygosity exclusion mapping by screening of closely flanking microsatellite markers at 181 known candidate genes/loci followed by sequencing of the candidate gene for pathogenic.
Results :
Of these 67 families subjected to homozygosity mappin, 38 showed homozygosity for at least one of the 181 regions and sequence analysis of the corresponding genes showed homozygous cosegregating mutations in 27 families. Overall, mutations were detected in approximately 63.9 % (92/144) of arRD families tested, with another 8.3% (12/144) being mapped to a locus but without a gene identified.
Conclusions :
These results suggest involvement of unmapped novel genes in the remaining 27.8% (52/144) of families. In addition, this study demonstrates that homozygosity mapping remains a powerful tool for identifying the genetic defect underlying genetically heterogeneous arRD disorders in consanguineous marriages for both research and clinical application
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.