The spectrum of COL4A1-related disorders included porencephaly (OMIM 175780) [53-55], Hereditary Angiopathy with Nephropathy, Aneurysm and Muscle Cramps (HANAC; OMIM 611773) [56], and brain small vessel disease with hemorrhage (OMIM 607595) [57]. Here, COL4A1 is linked to hemorrhage.