“…It is known, however, that the -α 3.7 deletion in heterozygosis, or homozygosis, is the most prevalent, due to the great miscegenation of the population with important African genetic contributions [ 5 , 6 , 7 ]. Studies in several Brazilian regions report variable frequencies of α + -thalassemia resulting from the -α 3.7 deletion, ranging from 0.7 to 20% [ 5 , 6 , 8 , 9 , 10 , 11 ]. After screening for the presence of microcytosis and/or hypochromia, the -α 3.7 deletion is detected in around 50% of individuals [ 12 , 13 ].…”