Background: Glucose-6-phosphate dehydrogenase (G6PD) is an X-Linked enzymopathy affecting about 400 million people worldwide. Neonatal jaundice, drug induced haemolysis and infection-induced haemolysis may happen in some deficient individuals and lead to considerable mortality. The distribution of G6PD deficiency and the molecular genetics of this enzyme vary widely among different ethnic groups. The aim of this study was to find out the frequency of G6PD deficiency and characterize the molecular type of this enzyme in deficient individuals in zanjan city.

Materials and Methods: One thousand and five hundred unrelated normal male individuals were screened for G6PD deficiency by fluorescent spot test. DNA was extracted from peripheral white blood cells of the individuals who were deficient for G6PD.polymerase chain reaction (PCR) was used to amplify flanking regions of exons six and seven of this gene using a set of primers. The PCR products were digested by the enzyme Mboll and electrophoresed on 2.5% agarose gel.

Results: Thirty three out of 1500(2.2%) individuals were shown to be deficient for G6PD enzyme. Twenty four out of 33 (72.7%) showed a mutation at nt 563 of G6PD gene which is characteristic of Mediterranean type of mutation. Nine individuals (27.3%) were negative for this mutation.

Conclusion: The results of this study showed that the prevalence of G6PD deficiency was lower comparing with that of other provinces. A direct correlation has been shown between G6PD deficiency and malaria in regions in which malaria was prevalent. Since the frequency of malaria is very low in zanjan, therefore, this rate of deficiency was justifiable for this region. Despite different frequencies existing for deficiency of G6PD in central, north, northwest ant southeast regions of Iran, the results of this study and other studies carried out by us and others have shown that the prevalence for Mediterranean type of G6PD in all the above regions are approximately the same. This may indicate that the predominant G6PD mutation in Iran is of Mediterranean type and this mutation is an old mutation too.