Unilateral vitelliform phenotype in autosomal recessive bestrophinopathy

Aims: It was the aim of this study to report on a patient in whom a novel mutation in the BEST1 gene was responsible for unilateral vitelliform phenotype in autosomal recessive bestrophinopathy (ARB). Methods: An 8-year-old young girl (proband) with unilateral vitelliform phenotype underwent a complete ophthalmologic examination at baseline (time of diagnosis) and 2 years later. Genomic DNA was extracted to look for BEST1 gene mutations in the patient and her parents. Results: Fundus autofluorescence imaging and spectral-domain optical coherence tomography showed unchanged findings in the right eye over the 2-year follow-up period. Conversely, both fundus autofluorescence imaging and spectral-domain optical coherence tomography showed a partial reabsorption of the hyper-autofluorescent/hyper-reflective subretinal material in the left macula over the 2-year follow-up period. On BEST1 gene analysis, the patient presented a novel mutation c.535-537delAAC (p.Asn179del) in homozygous condition; interestingly, despite the absence of parents' consanguinity, both the father and mother showed the same novel mutation in heterozygous condition. Conclusion: This case of unilateral vitelliform phenotype further supports the notion that ARB represents a disease spectrum in terms of severity, age at onset and heritability.