Objective  To report a novel BEST1 gene mutation in two patients with unilateral Best vitelliform macular dystrophy.

Methods  Best-corrected visual acuity, dilated fundus examination, and electro-oculography, fundus fluorescein angiography and autofluorescence photography were performed in the two patients with Best macular dystrophy and one of their relative. Both the patients and their relative also had blood samples drawn, direct sequencing of PCR-amplified DNA fragments, corresponding to the all 11 exons of the gene.

Results  A heterozygous BEST1 gene missense mutation in exon 4(Arg105Gly [CGC_GGC]) was identified in both patients. This mutation was not present in their relative and the other 50 normal peoples whose blood sample were analysis as control in this study. Clinical examination confirm that the lesions affected the patients unilaterally.

Conclusions  A novel mutation in the BEST1gene(C313G) was found in two chinese patients whose phenotype and electrooculographic findings were characteristic of  unilateral Best macular dystrophy.