Fabry's disease is a rare familial disorder of glycolipid metabolism which is caused by a deficiency of a lysosomal enzyme alpha-galactosidase. A Finnish family is described in which cornea verticillata was found in the father and 2 daughters. In all cases, there were symptoms suggesting Fabry's disease: febrile episodes the origin of which was not clear, limb pains and, in the case of the father, 20 years of proteinuria with elevated ESR, and hemiplegia and aphasia following a cerebral thrombosis at the age of 43. The diagnosis was confirmed by demonstration of an alpha-galactosidase deficit in the serum and urine of all patients. Deficiency of this enzyme leads to abnormally high urinary tri- and dihexosyl ceramide levels, and this was observed in the father and the elder daughter. At the age of 12, the daughter had loss of vision in her right eye as a result of occlusion of the central retinal artery. Electron microscopic (EM) examination of the father's dermal angioma suggested Fabry's disease. Computerized cranial tomography of the father revealed not only the cerebrovascular condition but also a disease affecting the white matter of the brain.