Angiopathy, Hereditary, with Nephropathy, Aneurysms, and Muscle Cramps, also known as autosomal dominant familial hematuria-retinal arteriolar tortuosity-contractures syndrome, is related to retinal arteries, tortuosity of and hemorrhage, intracerebral, and has symptoms including muscle cramp An important gene associated with Angiopathy, Hereditary, with Nephropathy, Aneurysms, and Muscle Cramps is COL4A1 (Collagen Type IV Alpha 1 Chain). Affiliated tissues include eye and kidney, and related phenotypes are renal insufficiency and multiple renal cysts