Best's macular dystrophy in Australia: Phenotypic profile and identification of novel BEST1 mutations

Purpose (1) To evaluate the spectrum of BEST1mutations within Australian Best Disease or vitelliform macular dystrophy (VMD) pedigrees, including any novel mutations; (2) to analyse the range of clinical presentations of this cohort; (3) to determine any possible genotype-phenotype correlations and (4) to compare clinical data of patients with phenotypic VMD, both with and without a BEST1mutation. Patients and methods Patients with suspected VMD were referred to clinical centres for ophthalmological assessment and genetic screening. When a mutation was identified in a proband, further family members were invited for clinical and genetic screening. Results We identified 42 patients with one of 13 BEST1mutations. Seven mutations were novel. There were a further 14 probands in whom a BEST1mutation was not identified. Median visual acuity in both VMD (mutation positive) and clinical VMD (no BEST1mutation identified) groups reached driving standards (6/12 or better). Conclusion We did not identify any firm genotype-phenotype correlations in our Australian VMD pedigrees, in which there was a spectrum of BEST1mutations and marked variation in clinical presentation. Genetic screening remains the gold standard for VMD diagnosis. Patients should be counselled that visual acuity might remain at or above driving standards in at least one eye even in the presence of a BEST1mutation.