Variable phenotypic expressivity of Best's vitelliform dystrophy.

Two families with Best's vitelliform macular dystrophy (BVMD) were investigated ophthalmoscopically and electrophysiologically. Pedigree examination confirmed the autosomal dominant heredity of this disorder with variable expressivity. Extrafoveal vitelline deposits were present in some asymptomatic patients, strongly suggesting that these deposits represent variable expressivity of familial BVMD.