Fabry's disease as a differential diagnosis of MS.

Fabry's disease is a genetically inherited error of glycosphingolipid metabolism that results from the defective activity of the lysosomal enzyme alpha-galactosidase A (alpha-GalA). The enzymatic defect, caused by an X-linked recessive genes, leads to progressive deposition of neutral glycosphingolipids (predominantly globotriaosylceramide), with terminal alpha-galactosyl moieties, in most visceral tissues and fluids of the body. Cerebrovascular manifestations result from multifocal small-vessel involvement and may include thromboses, basilar arterial ischaemia and aneurysm, seizures, paroxystic hemiplegia or hemianaesthesia, vestibular disorders and frank cerebral haemorrhage. Severe neurological signs may be present without evidence of major thrombosis and are presumably due to multifocal small-vessel occlusive disease. Vascular ischaemia and lipid deposition in peripheral nerves may cause conduction abnormalities (slowed conduction velocities and distal latency). Sensory neurons in spinal ganglia and small myelinated and unmyelinated fibers are affected preferentially.