Abstract
Purpose: :
Retinitis Pigmentosa (RP) is an inheritable, degenerative eye disease, renowned for its clinical and genetic heterogeneity. The disease is an important cause of blindness worldwide, especially in younger patients. Autosomal dominant RP can be caused by mutations in many genes, including PRPF31, which codes for the ubiquitously expressed splicing factor hPRP31. Over 30 mutations in this gene have so far been described, but in many patients with suspected PRPF31 mutations, no mutation has been identified. This is in part due to the limitations of technology thus far employed in the field and partly due to the huge genetic diversity of the disease. This project set out to detect large deletions in PRPF31 using the relatively new technique of multiplex ligation probe analysis (MLPA).
Methods: :
Nineteen patient DNAs were selected on the basis of clinical history and inheritance pattern. Ten of these underwent PCR amplification and sequencing; five of this set went on to be investigated with MLPA. Nine further DNAs (that had been previously sequenced) underwent MLPA analysis. Ten new individuals have been identified and are currently being analysed by MLPA, with the hope of identifying additional novel mutations in the PRPF31 gene.
Results: :
MLPA analysis detected 4 novel deletions within the PRPF31 gene. A further suspected large deletion was confirmed and it was possible to fully characterize this mutation as an 11,294 bp deletion. The other identified mutations are in the process of being characterized.
Conclusions: :
The identification of novel mutations in PRPF31 is important for the understanding of the pathogenesis of disease. It also has important implications for clinical diagnosis and genetic counselling of affected families. The ultimate aim of research in this area is the development of novel therapies that may lead to a cure for this devastating disease.
Keywords: retinal degenerations: hereditary • genetics • mutations