“…α-Thalassemia is estimated to affect around 5% of the population worldwide, with the -α 3.7 deletion being the most common alteration ( Piel and Weatherall, 2014 ). In Brazil, its prevalence is high ( Sonati et al , 1991 ; Couto et al , 2003 ; Adorno et al , 2005 ; Wagner et al , 2010 ; Cardoso et al , 2012 ; De Medeiros Alcoforado et al , 2012 ). However, Hb H disease, which is found primarily in Southeast Asia, the Middle East and the Mediterranean, has only rarely been reported in Brazil, where most cases are the result of an interaction of the -α 3.7 deletion with the -- MED , -(α) 20.5 , or -- SEA deletions ( Sonati et al , 1992 ; Wenning et al , 2000 , 2002 , 2009 ; Kimura et al , 2009 ).…”