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Introduction: Gallstone disease is a very common disease of gallbladder. Gallstone formation occurs when too much cholesterol is secreted into bile, leading to bile super-saturation and precipitation. Alteration in abcg8 protein which is one of the key transporters in gallbladder could result in increased bile cholesterol level. The aim of this study was to analyze the T400K genetic change that could have an effect on the function of this protein. Materials & Methods: This study was conducted on 220 people, dividing into two groups of cases (n=111) and controls (n=220). Genotyping was carried out by amplification of the target sequence followed by restriction fragment length polymorphism. Detection of any differences between cases and controls was done via statistic analysis. Findings: In this study, frequencies of the genotypes C/C, C/T and T/T were 59.5%, 39.5% and 1%, respectively. After statistical analysis of the data, there were no ass-ociations between this polymorphism and gallstone susceptibility. Discussion & Conclusion: The heterodimer protein, abcg5/abcg8, has a key role in the transportation of cholesterol in gallbladder and any changes in these proteins could result in gallstone formation. We could not find any association between T400K polymorphism and gallstone formation. This differentiation may be a result of genetic drifts among ethnic groups of populations.

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Background & Aim: Colorectal cancer (CRC) is the third common type of cancer and the second leading cause of death in cancer. DNA damages and chromosomal instability are the greatest risk factors favoring the development of CRC. Exo1 is the only exonuclease involved in the MMR system. In this study because of the important role of Exo1 and in order to assess the susceptible biomarkers associated with the CRC , we have investigated the correlation between SNP of Exo1 gene rs1047840 and risk of CRC. Material & Method: This case-control study was performed on 118 cases and 130 healthy controls who had been referred to Taleghani hospital of Tehran. We analysed genotyping using polymerase chain reaction- restriction fragment length polymorphism and using MseI restriction enzyme. Results: According to our findings the frequencies of AA, AG,GG genotypes in control group were 49/3%, 43/8% and 6/9% and in patient group were 44/9%, 47/5% and 7/6% . The frequency of G and A allels were 71/2% and 28/8% in healthy controls and 68/6% and 31/4% in patients. Conclusions: Base on our findings, rs1047840 polymorphism is not associated with susceptibility to CRC and so we reached on a conclusion that this polymorphism possibly doesn’t have significant role in increasing or decreasing risk of CRC.