5 M EDTA (Becton Dickinson, ) solution, carried on ice and kept at -70 ºC for DNA extraction. Because G6PD Mediterranean (C563T) is reported as the most common mutation in Middle East and some provinces of Iran, at first we analyzed all samples for this mutation.16 Finally 64 (55 males and 9 females) out of 231 samples were recognized without Mediterranean mutation, which were then analyzed to identify Cosenza mutation.Genomic DNA was extracted from leukocytes by using “PicoPure ” DNA extraction kit Inhibitors,research,lifescience,medical from Molecular Devices (San Diego, CA). mutation site is located

in exon 12 of G6PD gene. For detection of the Cosenza mutation, exon 11-13 of G6PD gene was selectively amplified by PCR method using F-cos (5´-GCA GCC AGT GGC ATC AGC AAG-3´) and R-cos (5´-GGG AAG GAG GGT GGC CGT GG-3´) primers.14 Inhibitors,research,lifescience,medical Polymerase chain reaction (PCR) assay was

performed in final volume of 25 μl. PCR reaction mix contained 10X PCR buffer, 10 mM of each deoxynucleotide triphosphate, 25 pmol of each primer, 0.5 μg genomic DNA, 2 U/ml of Taq DNA polymerase and 50 mM MgCl2. The PCR reaction was carried out for 30 cycles as follows: 10 cycles (94 ºC for 30 seconds, 68 ºC for 1 min and 72 Inhibitors,research,lifescience,medical ºC for 30 seconds) and 20 cycles (95 ºC, 65 ºC, 72 ºC each temperature for 1 min). In order to certify the fidelity of PCR, amplified segments were run on 1.5% agarose gel (figure 1). Since the mutation creates an Eco81I Romidepsin mouse recognition site (figure 2), this endonuclease was used to perform

Restriction fragment length polymorphism (RFLP) analysis. Cozenza PCR products were digested by Eco81I enzyme (Fermentas GmbH, ) at 37 ºC, overnight. The digested fragments were Inhibitors,research,lifescience,medical tested on 2% agarose gel. Figure 1 Polymerase chain reaction (PCR) products related to glucose-6-phosphate dehydrogenase Cosenza mutation on 1.5 % agarose gel. Lane 1: Size Marker 1 Kbp, Lane 2: negative control, Lanes 3, 4, 5, 6, 7, 8 and 9: Cosenza PCR products with 548 bp length Figure 2 Oligonucleotide Inhibitors,research,lifescience,medical primers F-cos and R-cos amplify a 548pb fragment across exon 11 and 13 of the glucose-6-phosphate dehydrogenase gene that after digestion by Eco81I appeared as two fragments with 232 bp and 316 bp Results Among the 231 G6PD deficient individuals (a total of 267 alleles), 195 (84.1%) were males and 36 were females. Only 64 samples (55 males and Thymidine kinase 9 females) out of 231 deficient subjects did not have G6PD Mediterranean. They were analyzed to characterize G6PD Cosenza Mutation, using PCR-RFLP method. Cosenza PCR product was a 548 bp fragment, which appeared as two fragments with 232 bp and 316 bp lengths after digestion by Eco81I on 2% agarose gel in mutant subjects (figure 3). The result showed that 6 males out of 231 samples had the Cosenza mutation. Therefore the mutation relative rate and allele frequency in Khuzestanian deficient subjects are 2.6% and 0.023, respectively. Fifty eight samples did not have Mediterranean and mutations.