Frequency Of Hereditary Persistance Of Fetal Hemoglobin Ad Structural Fetal Hemoglobin Variants In A Brazilian Population

We identified the -globin gene alterations present in 20 carriers of Hb Fetal structural variants and the prevalence and characteristics of Hereditary Persistence of Fetal Hemoglobin (HPFH) in a population of southeastern Brazil. The latter (HPFH) was screened from a survey which analyzed 47,468 adult out patients (80% Caucasians and 20% African descendants), attended at UNICAMP University Hospital, randomly chosen among those without hematological manifestations. Methods included electrophoresis on cellulose acetate at alkaline pH, Hb F estimation by alkali denaturation and globin-chain electrophoresis at acid pH. Hematological data were electronically determined. Fortythree individuals (approximately 0.1%) presented increased HbF levels, varying from 2.1% to 29.2%. Twenty-two (52% of the HPFH cases) had the normal proportion of the 2 different chains, 10 cases (23%) showed"; 4 (9%) had OA, and 7 (16%) presented only A. Only 2 cases were of African descent, all the others were mainly of Italian, Portuguese and Spanish descent. Hb and DNA samples from 20 newborns with abnormal Hb F detected in the sickle cell anemia newborn screening program were analyzed. Hb samples were submitted to the same tests above mentioned, while DNA samples were directly sequenced after selective amplification of the -genes. We found 4 different structural variants: 1 case of Hb Yamaguchi (AT 80 AspAsn) (GATAAT), detected in a Japanese descendant, 2 cases of Hb F Dickinson (AT 97 HisArg) (CATCGT) (carrier's origins not informed), 6 cases of Hb Port Royal (G 125 GluAla) (GAGGCG), of Italian and Spanish descent, and 11 cases of Hb F Carlton (G 121GluLys). These results represent the first information on the prevalence of HPFH in Brazil, and indicate the most prevalent -globin gene mutations in the population of this region of Brazil.9611 PART I