Siblings with infantile cerebral stroke and delayed multivessel involvement--a new hereditary vasculopathy?

We describe an unusual vasculopathy in two sisters of non-consanguineous parents. The first child developed an acute hemiparesis and focal seizures at the age of 6 months during a febrile illness. Magnetic resonance imaging (MRI) of the brain showed bilateral cortical-subcortical infarction not confined to a vascular territory. Subsequently, the child had a persistent stable neurological deficit. Her younger sister had a similar encephalitis-like episode at the age of 4 months, with left-sided cortical-subcortical ischaemic lesions. Two months later she had left-sided focal seizures. MRI showed a right-sided cortical enhancement, magnetic resonance angiography (MRA) was normal. The neurological deficit was stable and she was seizure free. These episodes were initially interpreted as metabolic strokes, but work-up was normal and mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) was excluded. In their teens both sisters were diagnosed with pulmonary and systemic hypertension and, due to the arterial hypertension, myocardial hypertrophy. Renal artery stenosis, pathological pulmonary arteries, and stenosis and rarefication of coronary arteries were found; the aorta and retinal vessels were normal. Repeat cranial MRI and MRA showed multiple collaterals, while the carotid and basilar arteries were extremely narrowed (moyamoya appearance). We suggest the diagnosis is a hereditary systemic vasculopathy of unknown origin.