Autosomal recessive bestrophinopathy

Autosomal recessive bestrophinopathy (ARB) is a rare inherited retinal dystrophy caused by biallelic (homozygous or compound heterozygous) mutations in the BEST1 gene, which encodes bestrophin-1, a calcium-activated chloride channel expressed in the retinal pigment epithelium (RPE). Unlike Best vitelliform macular dystrophy, which follows autosomal dominant inheritance and is caused by heterozygous BEST1 mutations, ARB results from loss of function of both copies of the gene and presents with a distinct and often more widespread retinal phenotype. ARB primarily affects the eyes, leading to progressive visual impairment. Key clinical features include diffuse RPE abnormalities, subretinal fluid accumulation, multifocal vitelliform deposits (yellowish lesions beneath the retina), and a markedly reduced or absent electro-oculogram (EOG) light rise, which is a hallmark of bestrophin-1 dysfunction. Patients may also develop cystoid macular edema, hyperopia (farsightedness), and a shallow anterior chamber, which can predispose to angle-closure glaucoma. The condition typically presents in childhood, and visual acuity may be relatively preserved early on but tends to decline progressively over time. Some patients may also exhibit features overlapping with other BEST1-related disorders. There is currently no cure or specific approved treatment for autosomal recessive bestrophinopathy. Management is supportive and includes regular ophthalmologic monitoring, correction of refractive errors, and management of complications such as glaucoma or choroidal neovascularization if they arise. Anti-VEGF injections may be considered for secondary choroidal neovascularization. Low-vision aids and rehabilitation services can help patients cope with progressive visual loss. Gene therapy approaches are under investigation for BEST1-related disorders, but no approved gene therapy is currently available for ARB.

Common questions about Autosomal recessive bestrophinopathy