Frank Arne Wollenweber1, Patrizia Hanecker1, Anna Bayer-Karpinska1, Rainer Malik1, Hansjörg Bäzner1, Fiona Moreton1, Keith W Muir1, Susanna Müller1, Armin Giese1, Christian Opherk1, Martin Dichgans1, Christof Haffner1, Marco Duering2. 1. From the Institute for Stroke and Dementia Research, Klinikum der Universität München (F.A.W., P.H., A.B.-K., R.M., C.O., M.D., C.H., M.D.), Institute for Pathology (S.M.), and Center for Neuropathology and Prion Research (A.G.), Ludwig-Maximilians-University, Munich, Germany; Department of Neurology, Klinikum Stuttgart, Stuttgart, Germany (H.B.); Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom (F.M., K.W.M.); Department of Neurology, Klinikum am Gesundbrunnen, SLK-Kliniken, Heilbronn, Germany (C.O.); and Munich Cluster for Systems Neurology (SyNergy), Munich, Germany (M.D.). 2. From the Institute for Stroke and Dementia Research, Klinikum der Universität München (F.A.W., P.H., A.B.-K., R.M., C.O., M.D., C.H., M.D.), Institute for Pathology (S.M.), and Center for Neuropathology and Prion Research (A.G.), Ludwig-Maximilians-University, Munich, Germany; Department of Neurology, Klinikum Stuttgart, Stuttgart, Germany (H.B.); Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom (F.M., K.W.M.); Department of Neurology, Klinikum am Gesundbrunnen, SLK-Kliniken, Heilbronn, Germany (C.O.); and Munich Cluster for Systems Neurology (SyNergy), Munich, Germany (M.D.). marco.duering@med.uni-muenchen.de.
Abstract
BACKGROUND AND PURPOSE: Mutations in NOTCH3 cause cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), the most common monogenic cause of stroke and vascular dementia. Misfolding and aggregation of NOTCH3 proteins triggered by cysteine-affecting mutations are considered to be the key disease mechanisms. However, the significance of cysteine-sparing mutations is still debated. METHODS: We studied a family with inherited small vessel disease by standardized medical history, clinical examination, MRI, ultrastructural analysis of skin biopsies, and Sanger sequencing of all NOTCH3 exons. In addition, we performed in vitro characterization of NOTCH3 variants using recombinant protein fragments and a single-particle aggregation assay. RESULTS: We identified a novel cysteine-sparing NOTCH3 mutation (D80G) in 4 family members, which was absent in a healthy sibling. All mutation carriers exhibited a CADASIL typical brain imaging and clinical phenotype, whereas skin biopsy showed inconsistent results. In vitro aggregation behavior of the D80G mutant was similar compared with cysteine-affecting mutations. This was reproduced with cysteine-sparing mutations from previously reported families having a phenotype consistent with CADASIL. CONCLUSIONS: Our findings support the view that cysteine-sparing mutations, such as D80G, might cause CADASIL with a phenotype largely indistinguishable from cysteine mutations. The in vitro aggregation analysis of atypical NOTCH3 mutations offers novel insights into pathomechanisms and might represent a tool for estimating their clinical significance.
BACKGROUND AND PURPOSE: Mutations in NOTCH3 cause cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), the most common monogenic cause of stroke and vascular dementia. Misfolding and aggregation of NOTCH3 proteins triggered by cysteine-affecting mutations are considered to be the key disease mechanisms. However, the significance of cysteine-sparing mutations is still debated. METHODS: We studied a family with inherited small vessel disease by standardized medical history, clinical examination, MRI, ultrastructural analysis of skin biopsies, and Sanger sequencing of all NOTCH3 exons. In addition, we performed in vitro characterization of NOTCH3 variants using recombinant protein fragments and a single-particle aggregation assay. RESULTS: We identified a novel cysteine-sparing NOTCH3 mutation (D80G) in 4 family members, which was absent in a healthy sibling. All mutation carriers exhibited a CADASIL typical brain imaging and clinical phenotype, whereas skin biopsy showed inconsistent results. In vitro aggregation behavior of the D80G mutant was similar compared with cysteine-affecting mutations. This was reproduced with cysteine-sparing mutations from previously reported families having a phenotype consistent with CADASIL. CONCLUSIONS: Our findings support the view that cysteine-sparing mutations, such as D80G, might cause CADASIL with a phenotype largely indistinguishable from cysteine mutations. The in vitro aggregation analysis of atypical NOTCH3 mutations offers novel insights into pathomechanisms and might represent a tool for estimating their clinical significance.
Authors: Ilaria Di Donato; Silvia Bianchi; Nicola De Stefano; Martin Dichgans; Maria Teresa Dotti; Marco Duering; Eric Jouvent; Amos D Korczyn; Saskia A J Lesnik-Oberstein; Alessandro Malandrini; Hugh S Markus; Leonardo Pantoni; Silvana Penco; Alessandra Rufa; Osman Sinanović; Dragan Stojanov; Antonio Federico Journal: BMC Med Date: 2017-02-24 Impact factor: 8.775
Authors: Laura L Kilarski; Loes C A Rutten-Jacobs; Steve Bevan; Rob Baker; Ahamad Hassan; Derralynn A Hughes; Hugh S Markus Journal: PLoS One Date: 2015-08-25 Impact factor: 3.240