[show abstract][hide abstract] ABSTRACT: To describe the finding of a novel calcium binding protein 4 (CABP4) mutation in a family with Leber congenital amaurosis (LCA) phenotype.
Homozygosity mapping was performed in a consanguineous family with four affected members originally referred as cases of LCA. Detailed electroretinographic recordings were obtained.
A novel homozygous single base-pair insertion was identified in all four siblings. The patients had an LCA-like phenotype, including either flat or greatly diminished electroretinographic activity.
This report significantly expands on the phenotype associated with calcium binding protein 4 mutations, which has so far been limited to congenital stationary night blindness, and further demonstrates how molecular data often blur the boundaries between what are believed to be clinically distinct retinal disorders.
[show abstract][hide abstract] ABSTRACT: To catalog mutations that underlie retinitis pigmentosa (RP) in Saudi Arabia using a representative sample.
Fifty-two patients with RP were recruited and their homozygosity mapping, with or without linkage analysis, was used to suggest the causative genes followed by bidirectional sequencing.
Mutations were identified in 94% of our study cohort, including seven that were novel.
Homozygosity mapping is an extremely robust approach in the study of retinitis pigmentosa in the setting of high rates of consanguinity. BBS3 mutations can rarely present as nonsyndromic RP.