Natalya Abramycheva1, Maria Stepanova1, Lyudmila Kalashnikova2, Maria Zakharova3, Marina Maximova4, Marine Tanashyan5, Olga Lagoda5, Ekaterina Fedotova1, Sergey Klyushnikov1, Rodion Konovalov6, Alla Sakharova7, Sergey Illarioshkin8. 1. Department of Neurogenetics, Research Center of Neurology, Russian Academy of Medical Sciences, Volokolamskoye Shosse 80, Moscow 125367, Russia. 2. Department of Neurorehabilitation, Research Center of Neurology, Russian Academy of Medical Sciences, Volokolamskoye Shosse 80, Moscow 125367, Russia. 3. Department of Demyelinating Diseases, Research Center of Neurology, Russian Academy of Medical Sciences, Volokolamskoye Shosse 80, Moscow 125367, Russia. 4. Department of Acute Stroke with Intensive Care Unit, Research Center of Neurology, Russian Academy of Medical Sciences, Volokolamskoye Shosse 80, Moscow 125367, Russia. 5. Department of Chronic Cerebrovascular Diseases, Research Center of Neurology, Russian Academy of Medical Sciences, Volokolamskoye Shosse 80, Moscow 125367, Russia. 6. Department of Neuroradiology, Research Center of Neurology, Russian Academy of Medical Sciences, Volokolamskoye Shosse 80, Moscow 125367, Russia. 7. Department of Pathology, Research Center of Neurology, Russian Academy of Medical Sciences, Volokolamskoye Shosse 80, Moscow 125367, Russia. 8. Department of Neurogenetics, Research Center of Neurology, Russian Academy of Medical Sciences, Volokolamskoye Shosse 80, Moscow 125367, Russia. Electronic address: snillario@gmail.com.
Abstract
BACKGROUND: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) is a cerebrovascular small-vessel disease caused by stereotyped mutations in the Notch3 gene altering the number of cysteine residues. METHODS: We directly sequenced exons 2-23 of the Notch3 gene in 30 unrelated Russian patients with clinical/neuroimaging picture suggestive of CADASIL. To confirm the pathogenicity of new nucleotide variants, we used the standard bioinformatics tools and screened 200 ethnically matched individuals as controls. RESULTS: We identified 16 different point mutations in the Notch3 gene in 18 unrelated patients, including 4 new missense mutations (C194G, V252M, C338F, and C484G). All but two mutations affected the cysteine residue. The non-cysteine change V322M was shown to be associated with CADASIL-specific deposits of granular osmiophilic material in the vascular smooth-muscle cells, which confirmed the pathogenicity of this Notch3 variant. Two patients were shown to be compound-heterozygotes carrying two pathogenic Notch3 mutations. The disease was characterized by marked clinical variability, without evident phenotype-genotype correlations. CONCLUSIONS: In our sample, 60% of Russian patients with 'clinically suspected' CADASIL received the definitive molecularly proven diagnosis. Careful assessment of genealogical, clinical, and neuroimaging data in patients with lacunar stroke can help selecting patients with a high probability of finding mutations on genetic screening.
BACKGROUND:Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) is a cerebrovascular small-vessel disease caused by stereotyped mutations in the Notch3 gene altering the number of cysteine residues. METHODS: We directly sequenced exons 2-23 of the Notch3 gene in 30 unrelated Russian patients with clinical/neuroimaging picture suggestive of CADASIL. To confirm the pathogenicity of new nucleotide variants, we used the standard bioinformatics tools and screened 200 ethnically matched individuals as controls. RESULTS: We identified 16 different point mutations in the Notch3 gene in 18 unrelated patients, including 4 new missense mutations (C194G, V252M, C338F, and C484G). All but two mutations affected the cysteine residue. The non-cysteine change V322M was shown to be associated with CADASIL-specific deposits of granular osmiophilic material in the vascular smooth-muscle cells, which confirmed the pathogenicity of this Notch3 variant. Two patients were shown to be compound-heterozygotes carrying two pathogenic Notch3 mutations. The disease was characterized by marked clinical variability, without evident phenotype-genotype correlations. CONCLUSIONS: In our sample, 60% of Russian patients with 'clinically suspected' CADASIL received the definitive molecularly proven diagnosis. Careful assessment of genealogical, clinical, and neuroimaging data in patients with lacunar stroke can help selecting patients with a high probability of finding mutations on genetic screening.
Authors: Dorothee Schoemaker; Yakeel T Quiroz; Heirangi Torrico-Teave; Joseph F Arboleda-Velasquez Journal: Neurosci Lett Date: 2019-01-08 Impact factor: 3.046