Phenotype and genetic spectrum of six Indian patients with bestrophinopathy

The aim of this study is to describe genotype and phenotype of patients with bestrophinopathy. The case records were reviewed retrospectively, findings of multimodal imaging such as color fundus photograph, optical coherence tomography (OCT), fundus autofluorescence, electrophysiological, and genetic tests were noted. Twelve eyes of six patients from distinct Indian families with molecular diagnosis were enrolled. Exon 4 of <i>BEST1</i> was mutated in 3 cases, while exons 2, 3, and 7 in others. Deletion is seen in Exon 7 and missense mutation in other exons. Sporadic autosomal dominant and recessive inheritance was observed in these families. Two patients had primary angle closure glaucoma with a history of consanguineous marriage and glaucoma in the family. Based on our findings, multifocal vitelliform subretinal deposits were the most common fundus finding in patients with autosomal recessive mutation while macular vitelliform lesion was seen with sporadic or autosomal dominant mutation; however, cosegregation analysis was not done. Baseline OCT showed macular and extramacular subretinal exudates, subretinal fluid, intraretinal cystic and schitic spaces, and thickened photoreceptors outer segment tips. Two patients developed abnormal vasculature and focal choroidal excavation in OCT. A severe reduction in the electro-oculogram Ardens ratio was noted while electroretinography was normal. Bestrophinopathy has a varied presentation with complex genotype-phenotype relationships. OCT is a noninvasive tool for monitoring and prognostication. Genetic testing of other family members should be facilitated.