genetic abnormality known to predispose to acute hemolytic anemia (AHA), which can be triggered by certain drugs or by infection. However, the commonest trigger is the ingestion of fava beans (Vicia faba), causing AHA (favism), which may be lifethreatening especially in children. G6PD deficiency is genetically highly heterogeneous, as nearly 200 different mutations have been observed in the G6PD gene. Methods: We have investigated the hematological and genetic features of acute favism in the Palestinian Gaza community utilizing 131 children hospitalized for G6PD deficiency induced AHA and comparing the findings with indices from the general Gaza population. Results: We discovered the polymorphic coexistence of three different G6PD deficiency genes (G6PD A-, G6PD Cairo, G6PD Med) in the Gaza society. We have found by comparison to the general population (485 adults and 466 newborns) that children with favism, in terms of relative frequency, G6PD A- was under-represented, whereas G6PD Med was overrepresented. We also found that the severity of anemia was significantly greater with G6PD Med and G6PD Cairo than with G6PD A-; and with G6PD Cairo, compared to the other two variants, there was greater hyperbilirubinemia, as well as persistence of mild anemia and reticulocytosis for as long as 4 months after recovery from favism. Conclusion: We conclude that children with G6PD A- deficiency are also susceptible to AHA, but demonstrate in direct comparison within this same population that G6PD Med and G6PD Cairo are more severe forms of deficiency than G6PD A-. Further, we show that the heretofore poorly studied G6PD Cairo may be associated with low-level, chronic hemolysis. This study illustrates favism is a significant public health problem in Gaza due to fava beans as a staple in the diet and the coexistence of polymorphic G6PD deficiency variants in the society. Favism is an easily preventable and manageable genetic disorder with the proper awareness, intervention and education programs.