Novel Presenting Phenotype in a Child With Autosomal Dominant Best's Vitelliform Macular Dystrophy

Best's macular dystrophy (BMD) usually manifests with visual failure in the first or second decade of life; however, there is a large variability in expressivity of the disease, and some patients have no manifestation other than a pathological electro-oculogram (EOG). Autosomal dominant Best's vitelliform macular dystrophy (AD-BVMD) has a very specific phenotype that varies with the stage of the disease. In recent years, the authors have seen description of another clinical entity known as autosomal recessive BMD. Herein, the authors describe a 5-year-old girl referred from a peripheral hospital for investigation with a positive family history of BMD. Clinical findings included best-corrected visual acuity of 0.325 and 0.300 in the right and left eyes, respectively, by Sonksen logMar test, full color vision, normal orthoptic examination, and a small degree of hyperopia consistent with age. Macular optical coherence tomography (OCT) showed intraretinal fluid cysts and EOG showed reduced Arden ratio. Genetic testing was done for the proband and her father, who were found to be heterozygous for c.37C>T p. (Arg13Cys). The proband's younger sister will be reviewed and followed up once of age. The authors identified a new phenotype of AD-BVMD; although this is a single patient, more young children with BMD can now be scanned with the availability of hand-held OCT with better knowledge of the phenotype.