A Swiss family with 14 members across 3 generations affected with PDR was examined. Eleven living family members were investigated using 6 markers surrounding the RDS and RHO loci. Linkage to two possible candidate genes, the RDS gene on chromosome 6p and the rhodopsin gene on chromosome 3q, could be excluded. The family provides evidence for genetic heterogeneity of PDR and is in agreement with heterogeneity in other retinal dystrophies. Further investigations are in progress to map the gene causing PDR in this family.
Lesions predominate in the central fundus and exhibit considerable phenotypic heterogeneity.
More than 60 different mutations in this gene have been described. The aim of the present study was to exclude or confirm the involvement of RDS or RHO in the pathogenesis of PDR in this family. Additionally, studying retinal PDR may contribute to a better understanding of age related macular degeneration. Patients with suspicious findings were further investigated by fluorescein angiography. Ages of the patients at the time of clinical examination ranged from 32 to 67 years.