Prevalence and molecular characterization of Glucose-6-Phosphate dehydrogenase deficient variants among the Kurdish population of Northern Iraq

Abstract

BackgroundGlucose-6-Phosphate dehydrogenase (G6PD) is a key enzyme of the pentose monophosphate pathway, and its deficiency is the most common inherited enzymopathy worldwide. G6PD deficiency is common among Iraqis, including those of the Kurdish ethnic group, however no study of significance has ever addressed the molecular basis of this disorder in this population. The aim of this study is to determine the prevalence of this enzymopathy and its molecular basis among Iraqi Kurds.MethodsA total of 580 healthy male Kurdish Iraqis randomly selected from a main regional premarital screening center in Northern Iraq were screened for G6PD deficiency using methemoglobin reduction test. The results were confirmed by quantitative enzyme assay for the cases that showed G6PD deficiency. DNA analysis was performed on 115 G6PD deficient subjects, 50 from the premarital screening group and 65 unrelated Kurdish male patients with documented acute hemolytic episodes due to G6PD deficiency. Analysis was performed using polymerase chain reaction/restriction fragment length polymorphism for five deficient molecular variants, namely G6PD Mediterranean (563 C→T), G6PD Chatham (1003 G→A), G6PD A- (202 G→A), G6PD Aures (143 T→C) and G6PD Cosenza (1376 G→C), as well as the silent 1311 (C→T) mutation.ResultsAmong 580 random Iraqi male Kurds, 63 (10.9%) had documented G6PD deficiency. Molecular studies performed on a total of 115 G6PD deficient males revealed that 101 (87.8%) had the G6PD Mediterranean variant and 10 (8.7%) had the G6PD Chatham variant. No cases of G6PD A-, G6PD Aures or G6PD Cosenza were identified, leaving 4 cases (3.5%) uncharacterized. Further molecular screening revealed that the silent mutation 1311 was present in 93/95 of the Mediterranean and 1/10 of the Chatham cases.ConclusionsThe current study revealed a high prevalence of G6PD deficiency among Iraqi Kurdish population of Northern Iraq with most cases being due to the G6PD Mediterranean and Chatham variants. These results are similar to those reported from neighboring Iran and Turkey and to lesser extent other Mediterranean countries.

Molecular Characterization of G6PD Deficient Variants in Nineveh Province, Northwestern Iraq

“…This variant is the most common variants in other parts of Iraq [6][7][8]. Our figures were similar to those reported in Baghdad and Sulymania, but lower than those of Duhok and the middle Euphrates provinces [6][7][8]10].…”

“…G6PD Chatham (1003, G?A) was found in only 1(1.64 %) of our deficient individuals and this figure is lower than those from other parts of Iraq [6][7][8] and also lower than many neighboring countries including Iran and most Eastern Mediterranean countries [15,22].…”

“…G6PD deficiency is quite prevalent in many countries in the Eastern Mediterranean areas, including Iraq [2][3][4][5][6][7][8][9] and several studies from Iraq had addressed the prevalence and the molecular basis of G6PD deficiency in Baghdad, Duhok, Sulaimania and middle Euphrates provinces; [6][7][8][9][10] however none are available from the northwestern province of Nineveh. The current study aimed at addressing the molecular basis of G6PD deficient variants in random males in the later province, and compares the results with those from other part from Iraq and surrounding countries.…”

Molecular Characterization of Glucose-6-Phosphate Dehydrogenase Deficiency among Jordanians

“…In addition, patients who were complaining of acute hemolysis when the samples were taken had falsely elevated enzyme activity due to a high reticulocyte count which have normal G6PD activity (table 1). G6PD Mediterranean is found in Arabs, Italians, Greeks and other Mediterranean populations, as well as in Middle Eastern, African and Asian ethnic groups [11,20,21]. The highest incidence is found among Kurdish Jews, with a frequency of 70% [3].…”

Prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency in malaria endemic region of Iran (Sistan and Baluchestan Province): Epidemiological profile and trends over time

“…In general, prevalence of G6PD deficiency varies worldwide and among different cities of a country; it ranged for neighboring countries from 1.8% in Pakistan, 3.1% in Afghanistan, 6.7% in Iran to 10.9% in Iraq [9,[22][23][24]. Also, in malarious regions of the world, the prevalence rate of G6PD deficiency was reported to be 8% on average [25] which is lower than that (12%) in the present study.…”