COL4A1 and congenital anomaly of kidney and urinary tract: COL4A1 mutations have been identified as a monogenic cause of cerebral SVD and are associated with stroke (table 2).S54, S55 Missense mutations of COL4A1 are also implicated in kidney disease such as hereditary angiopathy, nephropathy, aneurysms and cramps (HANAC) syndrome.S56 COL4A1 mutations have also been recently reported as a potential novel cause of autosomal-dominant congenital anomalies of the kidney and urinary tract (CAKUT) in humans (the most common cause of kidney disease under the age of 30).S57