A rare mutation in the HFE gene, called H63D, was found to be the cause of hereditary hemochromatosis, a condition marked by iron overload, that ultimately led to porphyria cutanea tarda (PCT) in a 21-year-old man in the U.S., a case report shows. This case demonstrates the occurrence of “PCT in the setting of previously undiagnosed HH [hereditary hemochromatosis] caused by [two copies of the] H63D mutation in the HFE gene, which has rarely been reported,” researchers wrote.