Favism, the commonest form of severe hemolytic anemia in Palestinian children, varies in severity with three different variants of G6PD deficiency within the same community.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common genetic abnormality known to predispose to acute hemolytic anemia (AHA), which can be triggered by certain drugs or infection. However, the commonest trigger is fava beans (Vicia faba) ingestion, causing AHA (favism), which may be life-threatening especially in children. G6PD deficiency is genetically highly heterogeneous, as nearly 200 different mutations have been observed. We have investigated the hematological features of acute favism in the Palestinian Gaza community that is characterized by the polymorphic coexistence of three different G6PD deficiency genes (G6PD A-, G6PD Cairo, G6PD Med). 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 over-represented. 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 4months after recovery from favism. This is the first report determining a differential impact of different G6PD mutations on the clinical features of favism in the same population and the same environment.

Hemolysis and Mediterranean G6PD mutation (c.563 C>T) and c.1311 C>T polymorphism among Palestinians at Gaza Strip.

BACKGROUND: The G6PD c.563 C>T deficient mutation is endemic among Mediterranean populations but its clinical significance is not well delineated. We set up to estimate the proportion of G6PD deficient children presenting with hemolytic anemia at Al Nasser Pediatric Hospital at Gaza Strip, Palestine. We then established the prevalence of c.563T Mediterranean mutation and its linkage to c.1311 C>T polymorphism in this population. DESIGN AND METHODS: G6PD deficiency was identified in children presenting with hemolytic anemia at Al Nasser Pediatric Hospital by spectrophotometric measurement of G6PD activity. G6PD exon 6 and exon 11 were amplified from genomic DNA and evaluated for c.563T mutation by sequencing and the c.1311T polymorphism by restriction fragment analysis. Seventy X-chromosomes (60 males and 5 females) from G6PD deficient patients and 40 X-chromosomes from a control group known to be not G6PD deficient were tested. RESULTS: Over 80% of these children presenting with hemolytic anemia were G6PD deficient and 34% of these had the Mediterranean G6PD deficient variant. The allelic frequencies of Mediterranean c.563T and c.1311T polymorphisms among G6PD deficient patients were 0.33 and 0.38 respectively. The c.1311T polymorphism was linked in 95.2% of patients with the Mediterranean mutation, an allele frequency of 0.87, compared to the control non-G6PD deficient group with an allele frequency of 0.18. CONCLUSIONS: We conclude that G6PD deficiency accounts for majority of hemolytic anemia encountered in Gaza children treated at Al Nasser Pediatric Hospital Emergency department. The Mediterranean mutation c.563T, while not accounting for a majority of G6PD deficiency, is common among G6PD deficient Gaza Strip Palestinians and is frequently, but not always, linked to the c.1311T polymorphism. This work provides a foundation for the population screening of Palestinians for G6PD deficiency and for investigations of ancestral origin of the Mediterranean variant in world populations.

Molecular heterogeneity of glucose-6-phosphate dehydrogenase deficiency in Gaza Strip Palestinians.

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) deficiency, affecting more than 500 million people worldwide, is one of the most common of inherited disorders. There are 186 G6PD mutations published, with mutational clustering within defined ethnic/racial groups. However comprehensive molecular characterization of ethnically associated G6PD mutants and their clinical implications are lacking. DESIGN AND METHODS: Eighty unrelated Palestinian children hospitalized for hemolysis were studied. G6PD activity was determined by quantitative spectrophotometry and G6PD mutations were analyzed by sequencing of gDNA. RESULTS: 65 of 80 children (81%) had G6PD deficiency, accounting for most of the hemolytic disease in this age group. G6PD Mediterranean(c.563T), African G6PD A-(c.202A/c.376G), and G6PD Cairo(c.404C) were common with relative allele frequencies of 0.33 [1], 0.26, and 0.18 respectively. Two other variants were discovered, G6PD Beverly Hills(c.1160A) mutation, and a novel G6PD missense mutation c.536G>A (Ser179Asn), designated G6PD "Gaza". Three samples exhibited enzyme deficiency without detectable exonic or exon/intron boundary mutations. CONCLUSION: G6PD deficiency accounts for the majority of diagnoses for hemolysis in Palestinian children (81%), providing support for newborn G6PD deficiency screening programs. We report unanticipated molecular heterogeneity of G6PD variants among Gaza Strip Palestinians greater than reported in neighboring Arab populations. We report a high proportion of affected children with G6PD Cairo, which was observed previously in only a single Egyptian, and a novel mutation G6PD "Gaza".