Sirs: Fabry’s disease is an X-linked disorder resulting from the deficient activity of the lysosomal hydrolase α-galactosidase A [3]. The enzymatic defect leads to the progressive accumulation of neutral glycosphingolipids with terminal α-galactosyl moieties in the lysosomes of vascular endothelial and smooth-muscle cells [3]. The main neurological presentations of affected hemizygous males are painful neuropathy, hypohidrosis and stroke [3, 13]. Although heterozygous female carriers are either asymptomatic or exhibit milder symptoms, especially corneal opacity [3], some cases with serious neurological complications have also been reported [3, 13]. Detailed studies of peripheral nerves in hemizygotes have given somewhat different results [6, 7, 11, 15, 16, 20–23], and to date only one morphometric study is available in a heterozygote [14]. In order to learn more about the nerve lesions of patients with different genotypes of Fabry’s disease, we performed a quantitative morphological light-and electron-microscopic study of sural nerve specimens obtained from two patients, one male and one female.