GSTM1 and phenylketonuria: The State of Minas Gerais, Southeastern Brazil, was found in phase IV of the NNSP and identifies six diseases: phenylketonuria (PKU), congenital hypothyroidism (CH), hemoglobinopathies (Hb), cystic fibrosis (CF), congenital adrenal hyperplasia (CAH) and biotinidase deficiency (BD).4