Abstract
Purpose:
Autosomal recessive bestrophinopathy (ARB) is an inherited retinal disease caused by homozygous or compound heterozygous mutation of the BEST1. The ophthalmic findings are characterized by yellowish-white subretinal deposits and flecks scattered in the posterior pole, fundus autofluorescence (FAF) abnormalities, and reduced Arden ratio of the electroocculograms (EOGs). There are several reports of ARB, but no Japanese patient has been reported. The purpose of this study was to report the genotype and phenotype of two Japanese families with ARB.
Methods:
Ophthalmologic examinations including BCVA, FAF, optical coherence tomography (OCT), and EOG were performed on the proband and family members. Mutations of the BEST1 were confirmed by directed sequencing.
Results:
Four patients from two unrelated Japanese families were diagnosed with ARB. One homozygous mutation, c.763C>T (p.R255W) was detected in two siblings of one family (a 21-year-old man and a 27-year-old woman). Compound heterozygous missense mutations, c.73C>T (p.R25W), c.584C>T (p.A195V), were identified in two siblings of the second family (a 42-year-old woman and a 45-year-old man). These mutations were previously reported in other ethnic groups. The Arden ratio of the EOG was reduced in the two patients tested. All patients had macular abnormalities, yellowish-white subretinal lesions, and abnormal FAF. However the ophthalmic findings were diverse among the four patients and the severity was varying even in the siblings having the same mutations.
Conclusions:
The ophthalmic features of the Japanese ARB patients were similar to previous reports. Our findings suggests that biallelic mutation of BEST1 causes ARB with varying degrees of severity.