Correlation of genetics and clinical phenotypes in Cantú patients, together with studies of transgenic mice expressing Kir6.1 and SUR2 with human Cantú mutations provide compelling evidence that those mutations in Kir6.1 and SUR2B that produce overactive vascular smooth muscle KATP channels cause systemic hypotension, which leads to the wide range of pathologies presenting in Cantú syndrome. This evidence concerns the gene ABCC9 and hypertrichotic osteochondrodysplasia Cantu type.