AIM:To definitively diagnose a Best vitelliform macular dystrophy(BVMD) pedigree by molecular genetic examination of vitelliform macular dystophy 2(VMD2) gene,and to provide the basis for gene diagnosis of Best disease·METHODS: Ophthalmological examinations were performed.Mutations in the coding regions of VMD2 gene was analyzed by polymerase chain reaction(PCR) and direct DNA sequencing.VMD2 mutation screening was performed in 100 normal controls·RESULTS: Funduscopic examination of the proband revealed vitelliform lesions in the maculae of both eyes.Fundus angiography didn’t show choroidal neovascularization.Mutation analyses found a heterozygous mutation c.886A>G(Asn296Asp) in exon 8 of VMD2 gene·CONCLUSION: A novel disease-causing mutation in VMD2 gene(Asn296Asp) is found in a Best disease family.Mutation screening of VMD2 gene can be used for definite diagnosis and genetic consultation of Best disease.The possibility of Best disease should not be neglected when a case has macular abnormality.