The most noteworthy vascular complaints in our cohort were two aortic ectasias, an arteriovenous fistula, an interatrial septal aneurysm and an intracranial aneurysm; all these issues, except one of the two z scores > 2, were recognized in adults harboring a COL5A1 null allele. The gene discussed is COL5A1; the disease is Dilatation of the cerebral artery.