Despite AOS mainly manifesting through terminal transverse limb defects and scalp aplasia cutis, several AOS patients also display CHDs.14,15 CADASIL is a vascular dementia syndrome caused by mutations in NOTCH3, resulting in degeneration of vascular smooth muscle cells (VSMCs) and white matter, together with ischemic strokes.16 Unfortunately, current treatments cannot cure these diseases and only aim at mitigating the symptoms. Here, NOTCH3 is linked to CADASIL.