[Neonatal screening of G6PD deficiency in Tunisia].

Abstract

The Glucose-6-phosphate dehydrogenase (G6PI) deficiency is the most common enzymopathy worldwide. WHO had classified Tunisia among countries that are moderately affected by this affection. However, no mass-screening reflecting the real incidence was realized. The aim of this study is to determine the prevalence of this enzymopathy and its molecular basis in Tunisia. A total of 1102 neonates, born in CMNT center of Maternity and of Neonatology of Tunis during the going periods from April, 2005 till May, 2005 and from June, 2006 till September, 2006, have been enclosed in the study. The samplings included 953peripheral venous blood and 149 blood cordon. Among 1102 samplings, only 976 were of use to the screening. In our mass-screening, we consider all newborns that were born in the CMNT during the period of study and were included in the screening. A dosage of the enzymatic activity was realized using spectrophotometric method. G6PD electrophoresis and molecular study by PCR/RFLP were realized for the overdrawn newborn children. Among 976 screening neonates, 43 individuals (4.4%) were found to be G6PD deficient by quantitative enzyme assay. Newborn affected were distributed in 23 boys and 20 girls (sex ratio of 1.15). The electrophoretic mobility and the molecular biology were realized for the affected newborn. Molecular characterization of 30 G6PD deficient neonates revealed that the G6PD A- was the most common and was detected in 20 of 43 individuals (66.7%), followed by G6PD Mediterranean that was detected in 6 (13.3%). At least, 4 other unknown mutations were not able to be determined by PCR/RFLP (n=4). In conclusion G6PD deficiency is frequent in our country, justifying a systematic neonatal screening, to avoid the arisen of grave consequences of this affection. The African variant is the most frequent in our country followed by the Mediterranean one.