Muscle and skin biopsies are a sensitive diagnostic tool in the diagnosis of CADASIL

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leuk oencephalopathy (CADASIL) is a microangiopathic syndrome. Although the defe ctive gene has been identified, genetic analysis may be effort some due to its large size and various mutations. Providing a reliable diagnostic marke r would therefore be helpful. Electron microscopy has revealed characterist ic electron-dense granular deposits in the basal lamina of vessels of patie nts with CADASIL. We investigated the sensitivity of skin and muscle biopsi es for diagnosing CADASIL. We examined 30 family members of three unrelated German families affected by CADASIL. In 14 of the 21 affected individuals we performed skin and muscle biopsies; two patients were clinically asympto matic. Under electron microscopy all muscle and skin biopsy specimens showe d patches of granular and electron-dense material in the basal layer of bot h arterioles and capillaries. These findings confirm that general microangi opathy is a typical feature of this syndrome and is present in the early ph ase of the disease with or without clinical manifestation. Thus, as electro n microscopy of skin biopsy specimens can establish the diagnosis of CADASI L with high certainty, it may be considered the method of first choice.