[Porphyria].

Porphyrias are caused by enzyme defects along the heme biosynthetic pathway. The first line diagnosis of porphyria is based on specific biochemical patterns of elevated porphyrins and porphyrin precursors in urine, feces, and blood. In clinically active disease accumulated porphyrin precursors and/or porphyrins lead to abdominal, neurologic, psychiatric, endocrine and cardiovascular symptoms, liver damage and/or skin photosensitivity. Porphyrias are classified into acute and nonacute forms. Patients with symptomatic (clinically active) acute hepatic porphyria, e.g. acute intermittent porphyria, porphyria variegata, hereditary coproporphyria, and aminolevulinic acid dehydratase deficiency porphyria, display accumulation of porphyrin precursors, 5‑aminolevulinic acid and porphobilinogen due to regulation disorder. In the non-acute forms of porphyria, such as porphyria cutanea tarda, erythropoietic porphyria, X‑linked protoporphyria and congenital erythropoietic porphyria, accumulated porphyrins lead to skin photosensitivity and occasionally also to severe liver damage. Several different options for treatment, proven and innovative ones, are available for most porphyrias.