Two new class III G6PD variants [G6PD Tunis (c.920A > C: p.307Gln > Pro) and G6PD Nefza (c.968T > C: p.323 Leu > Pro)] and overview of the spectrum of mutations in Tunisia

We screened 423 patients referred to our laboratory after hemolysis triggered by fava beans ingestion, neonatal jaundice or drug hemolysis. Others were asymptomatic but belonged to a family with a history of G6PD deficiency. The determination of enzymatic activity using spectrophotometric method, revealed 293 deficient (143 males and 150 females). The molecular analysis was performed by a combination of PCR-RFLP and DNA sequencing to characterize the mutations causing G6PD deficiency. 14 different genotypes have been identified : G6PD A^? (376A > G;202G > A) (46.07%) and G6PD Med (33.10%) were the most common variants followed by G6PD Santamaria (5.80%), G6PD Kaiping (3.75%), the association [c.1311T and IVS11 93c] (3.75%), G6PD Chatham (2.04%), G6PD Aures (1.70%), G6PD A^? Betica (0.68%), the association [ 376G;c.1311T;IVS11 93c] (0.68%), G6PD Malaga, G6PD Canton and G6PD Abeno respectively (0.34%). Two novel missense mutations were identified (c.920A > C: p.307Gln > Pro and c.968T > C: p.323 Leu > Pro). We designated these two class III variants as G6PD Tunis and G6PD Nefza. A mechanism which could account for the defective activity is discussed.