CERKLMutations and Associated Phenotypes in Seven Spanish Families with Autosomal Recessive Retinitis Pigmentosa

Abstract

Retinitis pigmentosa (RP) is a genetically heterogeneous group of inherited retinopathies. Up to now, 39 genes and loci have been implicated in nonsyndromic RP, yet the genetic bases of >50% of the cases, particularly of the recessive forms, remain unknown. A novel gene (CERKL) has been described as associated with RP26. It encodes a ceramide kinase that is assumed to be involved in sphingolipid-mediated apoptosis in the retina. This is a report of the phenotypes and genotypes of persons carrying disease-causing mutations in CERKL. Two hundred ten unrelated Spanish families with nonsyndromic autosomal recessive RP were analyzed for sequence variations. Seven of these families presented a mutation in CERKL. Nine affected persons of these families were clinically investigated, including visual field, electrophysiology, and fundus examination. The mutation p.Arg257ter was identified in the homozygous state in all seven affected families. The patients with this variation in CERKL presented a common phenotype with characteristic macular and peripheral lesions. This study presents the first genotype-phenotype correlation for persons carrying p.Arg257ter mutation and provides clues for a characteristic phenotype of these mutations among persons with autosomal recessive cases.