COL4A1 and cerebral small vessel disease: Over the last decades, several monogenic cerebral small vessel diseases (cSVD) have been reported, with the diagnostic value of some of the radiological features having been identified.1-5 Pontine autosomal dominant microangiopathy and leukoencephalopathy (PADMAL) is one of the hereditary cSVD that is caused by pathogenic variants in the COL4A1 3′ untranslated region (UTR).6  COL4A1 encodes collagen type IV alpha 1 chain.