Together with exome sequencing and targeted sequencing7,14, a total of seven individuals with P/LP variants in COL4A1/2 have been identified in the Australian CP Biobank (individuals tested: n = 333 individuals for COL4A2 and n = 604 for COL4A1), with a range of clinical signs, including hydrocephalus with antenatal IVH, porencephalic cysts, epileptic encephalopathy, periventricular leukomalacia, and schizencephaly with polymicrogyria and associated periventricular gliosis. This evidence concerns the gene COL4A2 and periventricular leukomalacia.