GSTM1 and phenylketonuria: In the city of Maringá, Paraná state, in the period from 2001 to 2006, the incidence in relation to the number of live births (LB), were PKU - 1:20,529; CH - 1:2,281; Hb - 1:3,421; CF - 1:10,264 and BD - 1:6,843 of LB.