Most common NOTCH3 mutations causing CADASIL or CADASIL-like cerebral small vessel disease: A systematic review

Georgina Boston1, Dan Jobson1, Toshiki Mizuno2

  • 1Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK.

Insights

This study identifies common NOTCH3 mutations in Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL). Certain genotypes correlate with white matter hyperintensities and disease severity, though overall phenotypes show similarities.

Area of Science:

  • Genetics and Neurology
  • Molecular Medicine
  • Neuroimaging

Background:

  • Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a genetic disorder impacting small cerebral arteries.
  • It is caused by mutations in the NOTCH3 gene, leading to progressive neurological decline.
  • Understanding genotype-phenotype correlations is crucial for predicting disease progression and management.

Purpose of the Study:

  • To identify the most prevalent NOTCH3 mutations associated with CADASIL globally.
  • To investigate the association between specific NOTCH3 genotypes and clinical phenotypes, particularly white matter hyperintensities on MRI.
  • To compare disease severity and age of onset across different common NOTCH3 mutations.

Main Methods:

  • Systematic literature review of clinical studies and genomic databases (1996-2023).
  • Identification of common NOTCH3 missense mutations in CADASIL patients.
  • Analysis of clinical records focusing on MRI findings (white matter hyperintensities) and disease characteristics for genotype-phenotype correlation.

Main Results:

  • The six most common NOTCH3 mutations are p.R75P, p.R133C, p.R141C, p.R169C, p.R182C, and p.R544C, with p.R133C being the most frequent.
  • Genotypes p.R75P, p.R141C, p.R182C, and p.R544C showed a strong association with white matter hyperintensities on MRI.
  • The p.R141C mutation was linked to increased disease severity and earlier onset compared to p.R544C, although overall phenotypic differences between these two were not statistically significant.

Conclusions:

  • Specific NOTCH3 mutations are strongly associated with key CADASIL phenotypes, particularly white matter changes visible on MRI.
  • While some mutations like p.R141C may indicate greater disease severity, the phenotypic spectrum for common mutations like p.R141C and p.R544C is largely overlapping.
  • Geographic distribution of mutations suggests potential founder effects or sampling biases in regions like China and Japan.