Cadasil - genetic and ultrastructural diagnosis. Case report.

Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a hereditary disorder which affects the cerebral vasculature due to mutations in the NOTCH 3 gene. The diagnosis may be established through genetic testing for detection of these mutations and/or by skin biopsy. We report a case of the disorder in a female patient, who presented recurrent transient ischemic attacks that evolved to progressive subcortical dementia. Neuroimaging disclosed extensive leukoaraiosis and lacunar infarcts. The genetic analysis for NOTCH 3 was confirmatory. The ultrastructural examination of the skin biopsy sample, initially negative, confirmed the presence of characteristic changes (presence of granular osmiophilic material inclusions [GOM]), after the analysis of new sections of the same specimen. The present findings indicate that negative findings on ultrastructural examinations of biopsy should not exclude the diagnosis of the disease and that further analyses of the sample may be necessary to detect the presence of GOM.