Glucose-6-phosphate dehydrogenase (G6PD) is a greatly polymorphic enzyme encoded by human X-linked gene. G6PD deficit is the most public enzymopathy in human with about 400 million people affected globally. It is the main controlling enzyme in the hexose monophosphate shunt catalase the oxidation of glucose-6-phosphate to 6-phosphogluconolacton and the creation of reducing equals in the form of NADPH to meet the cellular redox formal and its absence origin hemolytic anemia - favism and newborn jaundice. Mutation in this enzyme cause three major types of unusual phenotype, including Mediterranean, Chatham and Cosenza. In this study, by Rapid Genomic DNA Extraction (RGDE) method, from 90 blood samples of unrelated male and female patients with genetic deficiency of G6PD, DNA was removed and next digestion by Eco81I enzymes, in order to research for Cosenza mutation, they were analyzed by means of PCR-RFLP. Sequencing methods were used. Of 90 patients, one patient had a Cosenza mutation frequency of 1.01%. Eighty-nine patients (98.99%) were not affected by the Cosenza-type mutation. Accordingly, Cosenza mutation is not regarded as the most common mutation in Iranian North-west population.
