GSTM1 and sickle cell disease: In relation to α-thal, research using random samples from neonatal screening in the state of Minas Gerais has shown that 30% of newborns with sickle cell anemia also inherited the α-thal gene.27 This result is similar to those found in the states of São Paulo (23.7%),28 Bahia (29.1%) and Pernambuco (25.6%).10, 29 In the current study, 21.31% of the patients with Hb S also inherited the α-thal gene and therefore the frequency of α-thal in the Brazilian population is relatively high, with even higher prevalence among Afro-descendants.20, 24, 27