Prevalence of hemoglobin abnormalities in Kebily, (South of Tunisia)

(B)ackground: Hemoglobin abnormalities constitute a public health problem i n many countries in the world. In Tunisia, these disorders were thought to affect only the North-western population. However, the existence of hemoglo binosis concentration in Kebily in south Tunisia has been suggested by prev ious work. In order to estimate their frequencies, we performed a screening of hemoglobin abnormalities in the North-Kebily region, to establish a pre vention program of the homozygous forms. Methods: This screening concerned all 1(st) and 2(nd) grade primary school pupils in North Kebily. After a questionnaire, a blood sample was drawn fro m every child. Hemogram, sickling test, and hemoglobin electrophoresis at a lkaline pH were performed for all children. Hemoglobin electrophoresis at a cid pH and a specific hemoglobin A2 titration were performed for some child ren. Results: The study concerned 1 400 children, aged between 5 and 12 years, t he mean age was 7 years and 7 months +/-10 months. Consanguinity rate and c oefficient were respectively 44% and 2249.10(-5). Endogamy was very high. T he global rate of hemoglobin abnormalities was 9.4%. Drepanocytosis with a rate of 4.9% was the most frequent, followed by beta thalassemia (3.1%) and C hemoglobinosis (1.6%). These abnormalities were unequally distributed; v ery frequent in some localities, they were quite absent in others. Conclusions: This study revealed a hemoglobinosis concentration in Tunisia, which can be classified second after that of Beja in North-western Tunisia . The heterogeneous distribution of the hemoglobin abnormalities in North-K ebily region and the high consanguinity and endogamy rates constitute facto rs that promote homozygous and double heterozygous forms to arise and justi fy the elaboration of a preventive strategy.