Novel mutation in autosomal recessive bestrophinopathy in Japanese siblings.

PURPOSE

Autosomal recessive bestrophinopathy (ARB) is a disease that results from the mutations in the gene. It is characterized by multifocal yellowish lipofuscin deposits, cystoid macular edema, and subretinal fluid. Among approximately 270 mutations, only 40 that include both heterozygous and homozygous mutations are associated with ARB. However, very few ARB-related mutations have been reported in the Japanese population. Therefore, in this study, we aimed to identify mutations and describe the genotype-phenotype relationship in Japanese dizygotic twins presenting with ARB.

MATERIALS AND METHODS

We performed clinical examinations in Japanese dizygotic twin patients (male: 29 years) with ARB as well as whole-exome sequencing in seven family members of these twins.

RESULTS

In this study, we have reported on a novel mutation, the p. Phe151Cys mutation, associated with ARB in Japanese dizygotic twins who had bi-allelic p. Ala160Pro mutations in . The clinical features observed were binocular abnormalities of the fundus, such as multifocal yellowish subretinal deposits, cystoid macular edema, and subretinal fluid. The full-field electroretinography results were subnormal.

CONCLUSION

It was indicated that the novel mutations identified may be strongly correlated with binocular ARB. This study provides significant information of the genotype-phenotype association in Japanese ARB patients. Further, the genetic analysis that we performed was very useful for the differential diagnosis and might have implications in the development of future treatment modalities.