Comparison of patients with documented PCT and HCV infection, documented PCT without HCV, HCV infection without PCT and controls without HCV or PCT.

Single blood + urine sample uptake to investigate : mutations in HFE gene, uroporphyrinogen decarboxylase activity, HCV genotye, history of disease.

Inclusion Criteria:

• Porphyria cutanea tarda /HCV negative Porphyria cutanea tarda/ HCV positive HCV positive HCV negative controls