Dominant COL4A1 and COL4A2 mutations cause a multisystem disorder that is marked by clinical heterogeneity and variable expressivity and that is generally characterized by the presence of cerebrovascular disease with ocular, renal, and muscular involvement.
Mutations in the collagen genes COL4A1 and COL4A2 cause Mendelian eye, kidney and cerebrovascular disease including intracerebral haemorrhage (ICH), and common collagen IV variants are a risk factor for sporadic ICH.