Abstract
Purpose: :
Best disease (BVMD) is an autosomal dominant, bilateral and progresive retinal macular degeneration with variable clinical expression and complete penetrance. It is the second most common cause of juvenile macular degeneration, and is characterized by yellow lesions in the macula that decreased central visual acuity in later stages. Fundoscopic, retinal fluorangiography (FAG) and electroculogram (EOG) examinations support clinical diagnosis. BVMD is caused by mutations in the BEST1 gene which is located in 11q13. In the present study, we described the clinical and molecular analysis of two Mexican families with Best disease.
Methods: :
We included two Mexican families with three affected generations each. Probands underwent full ophthalmologic examination including fundus examination, FAG, EOG and OCT; all results were compatible with BVMD. Blood samples were obtained by venipuncture, and genomic DNA was extracted. PCR amplification of the 11 exons and the intron-exon junctions of the BEST1 gene was achieved using pairs of primers derived from the BEST1 sequence. PCR products were purified, then direct automated sequencing of BEST1 was performed with the Big Dye Terminator
Results: :
All affected subjects from family #1 showed a heterozygous missense mutation in exon 2 of the BEST1 gene, that causes amino acid 24 change from tryptophan to cysteine (W24C). Affected subjects from family #2 exhibited a heterozygous missense mutation in the exon 8 that replaces glutamine for lysine at residue 293 (Q293K).
Conclusions: :
We describe the clinical and molecular features of two Mexican families with Best vitelliform macular dystrophy. This is the first study of the molecular basis of Best disease in Mexican and Latin American families. The ophthalmologic findings in these cases are emphatized.
Keywords: macula/fovea • mutations • retina