Gene analysis and evaluation of the single founder effect in Japanese patients with Oguchi disease.

PURPOSE: To analyze mutations of the arrestin/S-antigen (SAG) gene in nine newly identified Oguchi disease patients, and to examine whether the 926delA (formerly called 1147delA) mutation in the SAG gene is inherited from a single founder.

METHODS

DNA samples were assayed for mutations around nucleotide 926 of the SAG gene by direct sequencing, and analyzed for polymorphisms at codon 403 and IVS6-18 of the SAG gene by restriction analysis of polymerase chain reaction products.

RESULTS

All nine newly identified patients were homozygous for the 926delA mutation and had the same haplotype at codon 403 and IVS6-18. These findings are identical to those of previous reports of four Japanese Oguchi disease patients.

CONCLUSIONS

Mutation 926delA of the SAG gene is the main cause of Oguchi disease in Japanese. This mutation appears to have been inherited from a single founder.