ABCC6 causes PXE through biallelic mutations, and symptoms related to CSVD were previously reported in PXE.30 Mutations in ABCC6 are more frequent in ischaemic stroke patients, including CSVD.31 Our results indicate that ABCC6 mutations may be strong risk factor of severe CSVD, even in the heterozygous state. Here, ABCC6 is linked to pseudoxanthoma elasticum (inherited or acquired).