<prompt> Which of the following is not true about Porphyria cutanea tarda PCT?Is the least common type of human porphyriaDecreased activity of the enzyme uroporphyrinogen decarboxylasePrior hepatitis C virus infection appears to be an independent risk factorTreatment of PCT consists of repeated phlebotomies  <response>: Porphyria cutanea tarda is the most common type of human porphyria and is associated with decreased activity of the enzyme uroporphyrinogen decarboxylase associated with a number of gene mutations. 