The spectrum of COL4A1-related disorders includes small-vessel brain disease of varying severity including porencephaly, variably associated with eye defects (retinal arterial tortuosity, Axenfeld-Rieger anomaly, cataract) and systemic findings (kidney involvement, muscle cramps, cerebral aneurysms, Raynaud phenomenon, cardiac arrhythmia, and hemolytic anemia). The disease is Monarch Disease Ontology entry MONDO_0800461 (COL4A1-related disorder). Also known as: COL4A1-related disorders.