Hereditary coproporphyria.

Hereditary coproporphyria, a form of acute hepatic porphyria, is a rare Mendelian autosomal dominant inherited condition with incomplete penetrance. The acute attack is usually followed by complete remission, but death may occur. Latent cases are recognised, and the characteristic neurovisceral symptoms and signs are shared by many other conditions. Acute porphyria should be considered in the differential diagnosis of any patient presenting with abdominal pain and neuropsychiatric upset.