[Pathogenesis of porphyria cutanea tarda].

Porphyria cutanea tarda (PCT) results basically from decreased activity of uroporphyrinogen decarboxylase (UROD) in the liver. PCT is not a homogeneous disease; it can be either inherited or acquired. Not only alterations at the UROD gen locus but also other genetic factors outside the locus take part in the inactivation of UROD, that support polygenic inheritance of PCT. In every case, acquired factors take also part in development of the overt form of PCT. Iron has a key-role in the oxidative damages.