Prevalence of G6PD Deficiency in Iran

LETTER TO ETITOR G6PD (Glucose-6-Phosphate Dehydrogenase) enzyme deficiency is the most common inherited enzyme deficiency so far reported. 1 This enzyme deficiency affects 400 million people worldwide. 2 Most cases of the disease are from tropical regions of Africa, the Middle East, tropical and subtropical regions of Asia and the Mediterranean margin, arise from the process of natural selection. 2-4 The majority of cases of this enzyme deficiency (about 50%) have been reported in male Kurdish Jews. 5 Up to now, more than 160 mutations associated with G6PD enzyme deficiency have been reported. 6 G6PDA-genotype is a specific variant caused by A376G and G202A mutations. 7 G202A mutation is responsible for 95% of the reported cases of G6PDA-variantin Africa. Moreover, G6PD-santamaria forms a class II variant with low prevalence caused by two simultaneous mutations in nucleotides 376 and 524 of the code in gexons of G6PD gene. This genotype was first identified in Costa Rica, and is also found with low prevalence in southern Italy. 8 Large deletion, nonsense and frameshift mutations resulting in complete elimination of G6PD production are fundamentally incompatible with human life. Furthermore, no mutation has been reported in the coding region of the active enzyme site or in the promoter region. It is noteworthy that polymorphisms in non-coding sequences of G6PD are also involved in causing deficiency of G6PD enzyme. The exact mechanism of this enzyme deficiency remains unknown. 9 Malarious regions are important because of the high incidence of G6PD enzyme deficiency. In the Middle East, there are many cases of G6PD enzyme deficiency in Iran, Oman and Saudi Arabia. Various cities and provinces of Iran have been studied for prevalence of the variants of G6PD enzyme deficiency. In Golestan Province, 69% of the variants were related to Mediterranean variant and 26.7% were the Chatham variant. 10 In a descriptive study conducted in Zanjan to determine the frequency of G6PD enzyme deficiency and review the type of defect in molecular level, it was shown that the prevalence of G6PD deficiency in Zanjan is lower than some other provinces. The incidence of malaria in Zanjan is low, and can be justified with low prevalence of enzyme deficiency in this city. In this survey, it was found that most people in this area have a Mediterranean-type mutation at position 563 of G6PD gene. 11 In other studies carried out in Tehran, the dominant (73.4%) incidence of Mediterranean-type …