A curious case of small vessel vascular dementia

Pedigree of the patient's family showing the autosomal dominant inheritance pattern of disease transmission Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy is caused by cysteine-altering pathogenic variants in the NOTCH3 gene, with consequent vasculopathic changes, predominantly involving small penetrating arteries, arterioles, and brain capillaries.1 2 The mutation leads to an odd number of cysteine residues with deposition of osmiophilic material and progressive degeneration of vascular smooth muscle cells.1 2 The key to diagnosis includes a strong family history of young-onset stroke, an absence of strong vascular risk factors, and salient findings on brain magnetic resonance imaging, especially extensive white matter abnormalities and subcortical infarcts involving external capsules. Genetic testing for the NOTCH3 gene can be arranged after consultation with chemical pathologists in major public hospitals.3 4 The principle of management for symptomatic patients is similar to that of other patients with stroke, ie, antiplatelet therapy, lipid-lowering agents, and blood pressure control. Whitney CT Ip 1; YF Shea 1; HF Tong 2,3; CY Law 2; CW Lam 2,4; Patrick KC Chiu 1 1 Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China 2 Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong SAR, China 3 Department of Pathology, Princess Margaret Hospital, Hong Kong SAR, China 4 Department of Pathology, The University of Hong Kong, Hong Kong SAR, China