Medicine & USMLE

Porphyria Cutanea Tarda (PCT)

Heme and Porphyrias
  1. Heme Synthesis
  2. Acute Intermittent Porphyria (AIP)
  3. Porphyria Cutanea Tarda (PCT)

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.

Find Porphyria Cutanea Tarda and more Hematology topics among Pixorize's visual mnemonics for the USMLE Step 1 and NBME Shelf Exams.