EBioMedicine (Sep 2024)

Clinical and neuroradiological spectrum of biallelic variants in NOTCH3Research in context

  • Pablo Iruzubieta,
  • César Augusto Pinheiro Ferreira Alves,
  • Aisha M. Al Shamsi,
  • Gehad ElGhazali,
  • Maha S. Zaki,
  • Lorenzo Pinelli,
  • Diego Lopergolo,
  • Bernard P.H. Cho,
  • Amy A. Jolly,
  • Amna Al Futaisi,
  • Fatema Al-Amrani,
  • Jessica Galli,
  • Elisa Fazzi,
  • Katarina Vulin,
  • Francisco Barajas-Olmos,
  • Holger Hengel,
  • Bayan Mohammed Aljamal,
  • Vahideh Nasr,
  • Farhad Assarzadegan,
  • Michele Ragno,
  • Luigi Trojano,
  • Naomi Meave Ojeda,
  • Arman Çakar,
  • Silvia Bianchi,
  • Francesca Pescini,
  • Anna Poggesi,
  • Amal Al Tenalji,
  • Majid Aziz,
  • Rahema Mohammad,
  • Aziza Chedrawi,
  • Nicola De Stefano,
  • Giovanni Zifarelli,
  • Ludger Schöls,
  • Tobias B. Haack,
  • Adriana Rebelo,
  • Stephan Zuchner,
  • Filiz Koc,
  • Lyn R. Griffiths,
  • Lorena Orozco,
  • Karla García Helmes,
  • Meisam Babaei,
  • Peter Bauer,
  • Won Chan Jeong,
  • Ehsan Ghayoor Karimiani,
  • Miriam Schmidts,
  • Joseph G. Gleeson,
  • Wendy K. Chung,
  • Fowzan Sami Alkuraya,
  • Bita Shalbafan,
  • Hugh S. Markus,
  • Henry Houlden,
  • Reza Maroofian

Journal volume & issue
Vol. 107
p. 105297

Abstract

Read online

Summary: Background: NOTCH3 encodes a transmembrane receptor critical for vascular smooth muscle cell function. NOTCH3 variants are the leading cause of hereditary cerebral small vessel disease (SVD). While monoallelic cysteine-involving missense variants in NOTCH3 are well-studied in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), patients with biallelic variants in NOTCH3 are extremely rare and not well characterised. Methods: In this study, we present clinical and genetic data from 25 patients with biallelic NOTCH3 variants and conduct a literature review of another 25 cases (50 patients in total). Brain magnetic resonance imaging (MRI) were analysed by expert neuroradiologists to better understand the phenotype associated with biallelic NOTCH3 variants. Findings: Our systematic analyses verified distinct genotype-phenotype correlations for the two types of biallelic variants in NOTCH3. Biallelic loss-of-function variants (26 patients) lead to a neurodevelopmental disorder characterised by spasticity, childhood-onset stroke, and periatrial white matter volume loss resembling periventricular leukomalacia. Conversely, patients with biallelic cysteine-involving missense variants (24 patients) fall within CADASIL spectrum phenotype with early adulthood onset stroke, dementia, and deep white matter lesions without significant volume loss. White matter lesion volume is comparable between patients with biallelic cysteine-involving missense variants and individuals with CADASIL. Notably, monoallelic carriers of loss-of-function variants are predominantly asymptomatic, with only a few cases reporting nonspecific headaches. Interpretation: We propose a NOTCH3-SVD classification depending on dosage and variant type. This study not only expands our knowledge of biallelic NOTCH3 variants but also provides valuable insight into the underlying mechanisms of the disease, contributing to a more comprehensive understanding of NOTCH3-related SVD. Funding: The Wellcome Trust, the MRC.

Keywords