Abstract
Purpose: :
To determine the prevalence of BEST1 mutations in Best disease.
Methods: :
Clinical, electrophysiological and molecular retrospective study.The database of an outclinic patient unit specialised in genetic sensory diseases was screened for patients with presumed Best disease. Thirty-two patients (20 families) were included. The 12 exons and flanking intron sequences of BEST1 were screened in the 20 unrelated probands. Three microsatellites markers flanking BEST1 were used for haplotyping analysis.
Results: :
Best disease patients had a BEST1 mutation in half the cases (n=10 families), including one patient presenting multiple vitelliform deposits who was compound heterozygote, leading to the diagnosis of bestrophinopathy. In those patients with no BEST1 mutations (n=10 families), the Arden ratio was reduced in 6 of them. Members of a 3-generation family without BEST1 mutation showed consistent onset of the disease at age 20-25 and a normal EOG. In this family, segregation analysis of microsatellite markers excluded BEST1 as the causal gene.
Conclusions: :
Vitelliform macular dystrophies could be classified in 3 subgroups: typical BD with BEST1 mutations and reduced EOG; Best-like dystrophy with no BEST1 mutation and normal EOG and cases with no BEST1 mutation but reduced EOG. The absence of mutations in BEST1 in some families suggests the implication of additional genes in Best disease.
Keywords: genetics • gene screening • retina