Abstract
Purpose:
The purpose of this study was to analyze BEST1 gene mutations in Chinese patients with vitelliform macular dystrophy and to describe clinical features of these patients.
Methods:
Thirteen patients from twelve unrelated Chinese families affected by vitelliform macular dystrophy were recruited and clinically evaluated with best-corrected visual acuity examination, slit lamp biomicrocopy, fundus examination and photography, optical coherence tomography scan and fundus autofluorescence. Blood samples were collected for DNA extraction. Mutation analysis was performed by direct sequencing of the BEST1 gene. One hundred control chromosomes were also screened to exclude nonpathogenic polymorphisms.
Results:
Seven patients were found to have heterozygous mutations compatible with autosomal dominant inheritance. Two novel mutations (T4I and A291V) and three reported mutations (R218C, Q293H and D301G) were identified among these patients. Six patients were found to carry BEST1 mutations on both alleles. Homozygous mutations were detected in two patients who showed autosomal recessive bestrophinopathy phenotype while compound heterozygous mutations were detected in four patients who presented a Best vitelliform macular dystrophy phenotype. Mutation analysis revealed eight mutations among them. Four (Y33H, R130L, M163R and c.519delA) were novel and four (R13H, A195V, R255W and W287X) had already been reported.
Conclusions:
Patients with biallelic BEST1 mutations were common among Chinese bestrophinopathy patients and they displayed variability in phenotypes. The features and the combination of the different BEST1 mutations, as well as other genetic modifiers and/or environmental factors may influence phenotype expression. Our results expand the BEST1 mutations spectrum and may facilitate diagnostic modalities.
Keywords: 537 gene screening •
604 mutations •
494 degenerations/dystrophies