Autosomal recessive bestrophinopathy (ARB) results from a total absence of functional bestrophin-1 protein owing to two BEST1 mutations, one on each of the chromosomes.
Two novel combinations of missense mutations in the BEST1 gene were identified: p.R141H/p.M325T in three patients with ARB in two unrelated Norwegian families, and p.R141H/p.I201T was found in an ARB patient in a Swedish family.
To describe the presenting features and functional outcomes in a series of patients with choroidal neovascular membrane complicating BEST1-related retinopathy (Best disease and autosomal recessive bestrophinopathy).
ARB is a rare retinal disorder.We contribute a novel patient report indicative of ARB, assessed by clinical examination and confirmed by genotyping of BEST1, to the short list of ARB cases in the literature.
Both ARB patients harbored either proven (patient 1; c.102C>T p.Gly34Gly and c.572T>C p.Leu191Pro) or presumed (patient 2; c.102C>T p.Gly34Gly and c.1470_1471delCA, p.His490GlnfsX24) biallelic mutations in BEST1 and were found to have phenotypes consistent with ARB.
Mutations in the BEST1 gene cause the retinal dystrophies vitelliform macular dystrophy, autosomal-dominant vitreochoroidopathy, and autosomal-recessive bestrophinopathy.
As demonstrated in these consanguineous families, a great clinical variability is associated with homozygous mutations in BEST1, ranging from severe dominant BVMD with reduced penetrance in heterozygotes to autosomal recessive bestrophinopathy.
Mutations in the BEST1 gene cause the retinal dystrophies vitelliform macular dystrophy, autosomal-dominant vitreochoroidopathy, and autosomal-recessive bestrophinopathy.
However, it showed larger currents than other BEST1 mutants, p.Trp93Cys, causing autosomal dominant best vitelliform macular dystrophy (BVMD), and p.Ala195Val, causing autosomal recessive bestrophinopathy (ARB).
A clinical picture similar to autosomal recessive bestrophinopathy can also be caused by a single heterozygous mutation in the BEST1 gene, such as the c.614T>C (p.I205T) variant in this family.