Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) characteristics in Japan: variety of clinical features

Heterozygous Cysteine-sparing NOTCH3 Variant p.Val237Met in a Japanese Patient with Suspected Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy

A 64-year-old Japanese man with recurrent cerebral ischemic events and cognitive impairment was suspected of having cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) because of a family history and brain magnetic resonance imaging findings of cerebral white matter hyperintensities. The cysteine-sparing variation p.Val237Met was identified in NOTCH3. An intensive skin biopsy showed negative results (no granular osmiophilic material or positive NOTCH3 immunostaining), suggesting that the patient's definite diagnosis and pathogenicity of p.Val237Met were uncertain. We additionally reviewed previous reports of two Japanese families with p.Val237Met.

Clinical Features of CADASIL

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a rare hereditary disease characterized by recurrent transient ischemic attacks, strokes, and vascular dementia. Various mutations in the Notch3 gene cause the disease, whereas the mechanism of how they cause the disorder remains unknown. We recently identified two Japanese CADASIL families with an R141C mutation. The mean age of onset was 44.6, and the main symptoms were recurrent strokes and progressive motor disturbances in extremities, as well as pseudobulbar palsy. Besides those in white matter and basal ganglia, ischemic lesions in temporal edge and corpus callosum were present on magnetic resonance images, which seemed to be characteristic of CADASIL. Moreover, in our cases, nocturnal arterial blood pressure fall was significantly lower in patients compared with control subjects, suggesting that it might be partly associated with ischemic lesions in deep white matter in CADASIL. We also compared Japanese and Caucasian CADASIL cases and found that dementia and pseudobulbar palsy were observed more frequently in Japanese patients, although typical migraine was rather rare. In the present study, we describe the clinical features of CADASIL, hoping to help reveal the mechanism of chronic ischemic brain diseases, including leukoaraiosis or Binswanger's disease.