Precipitating factors of porphyria cutanea tarda in Brazil with emphasis on hemochromatosis gene (HFE) mutations. Study of 60 patients - Vieira, Fatima Mendonca Jorge; Nakhle, Maria Cristina; Abrantes-Lemos, Clarice Pires; Cancado, Eduardo Luiz Rachid; Reis, Vitor Manoel Silva dos (Anais Brasileiros de Dermatologia, 2013)