Porphyria Cutanea Tarda (PCT)
Heme and Porphyrias
Porphyria cutanea tarda (PCT) is the most common type of porphyria, and it results from a defective uroporphyrinogen decarboxylase enzyme, usually due to a sporadic mutation. The uroporphyrinogen decarboxylase enzyme is involved in Heme Synthesis at the conversion of uroporphyrinogen to coproporphyrinogen.
Although the causative mutation is sporadic, the development of PCT is associated with Hepatitis C. Elevated uroporphyrinand upstream heme precursors cause the clinical findings of PCT, which include tea-colored urine, and cutaneous findings such photosensitivity and hyperpigmentation.
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