Investigation of rs7903146 Polymorphism in TCF7L2 Gene in Patients with Type 2 Diabetes

Diabetes as a heterogeneous disease is characterized by a decrease in insulin sensitivity and a defect in insulin secretion. In general, diabetes is divided into four groups, type 1 diabetes, type 2 diabetes, gestational diabetes, and diabetes of various causes. To be Emerging evidence suggests that common and rare genetic polymorphisms can influence the risk of diabetic complications. Type 2 diabetes is a heterogeneous group of disorders that is usually characterized by the inability of pancreatic beta cells to increase insulin secretion to compensate for insulin resistance in peripheral tissues. Type 2 diabetes has been diagnosed in adults and is related to obesity, lifestyle, age, family history, and genetics. Genetically, many gene polymorphisms are known to be associated with this disease. The cause of type 2 diabetes is a mixture of lifestyle and genetic factors, while a person can control some of these issues such as diet and obesity, other issues such as aging, being female, and genetics cannot be controlled. However, until now, the exact cause of this disease has not been determined and its prevalence rate is also increasing. In the last decade, the prevalence of this disease has increased alarmingly in Iran. The single nucleotide polymorphism 7903146rs is located in intron number 3 of the TCF7L2 gene, which is significantly associated with type 2 diabetes. The expression of TCF7L2 in pancreatic cells of type 2 diabetic patients compared to healthy individuals was reported to be accompanied by a decrease in insulin secretion. Apart from the effect of the TCF7L2 variant on cell structure and insulin release from the beta pancreas, several studies have also reported a decrease in insulin secretion in response to the increased expression of TCF7L2 in the pancreas. The TCF7L2 gene is a transcription factor involved in the Wnt signaling pathway, which plays an important role in the development of pancreatic islets and fat. The TCF7L2 gene is considered one of the most important candidate genes for T2DM and plays an important role in blood glucose homeostasis and function. It has beta cells. The rs7903146 variant is one of the most important variants that has been proven to be related to diabetes in other populations, but so far no study has been conducted in East Azerbaijan on the relationship between the role of TCF7L2 in the development of type 2 diabetes, so the present study aims to investigate the relationship between poly The Morphism of rs7903146 in the TCF7L2 gene was performed in patients with type 2 diabetes in East Azerbaijan.

101 unrelated patients were invited to the diabetes clinic to provide blood samples. The basic information of the patients such as BMI, gender, and age was recorded in a questionnaire, and to comply with the ethical principles, a tracking code was inserted at the top of each questionnaire. Also, 101 unrelated healthy people were selected from the general population to call the control subjects. In this study, about 2 cc of blood samples were taken from each person and collected in tubes containing EDTA. The collected samples were transferred to the laboratory with a flask containing dry ice and kept at -20°C until extraction. The tubes containing the blood samples of patients and controls were numbered separately, and their gender was also noted on the tubes. After DNA extraction from all samples and quality assessment of the samples with specific primers, PCR and electrophoresis were performed. Took finally, the PCR products were treated with RSal restriction enzyme and electrophoresed again, and the target polymorphism was checked.

The frequency of genotypes was found as TT=33.7, CC=16.8, and CT=49.5 (percentage) for healthy people and the frequency of genotypes in sick people was found as TT=43, CC=14, and TC=43. = (percentage) was calculated. The percentage of the T allele in healthy and sick people was reported as 42.1% and 64.5%, respectively, and the percentage of the C allele in healthy and sick people was reported as 57.9% and 35.5%, respectively.

Because today diabetes is spreading all over the world as an unprecedented epidemic and also considering the role of genetic factors in the development of type 2 diabetes, it is necessary to investigate the genes related to this disease. It seems in the present study, the results showed that the frequency of the C allele, which is the dominant allele, is 57.9% in the healthy group, and 35.5% in the patient group, which shows a 22% decrease, and the frequency of the T allele, which is the polymorphism allele. It is 42.1% in the healthy group and 64.5% in the patient group, which 22% increase in the patient group shows that there is probably a relationship between the increase of the T allele and the risk of type 2 diabetes and the risk The incidence rate in the patient group is 2.501, and since it is more than one, there is a risk of contracting the disease, while the risk rate in the healthy group is 638.00, which is less than one. On the other hand, the frequency of genotypes was found as TT=33.7, CT=16.8, and CC=49.5 (percentage) for healthy people, and in sick people, the genotype frequency was as TT=43, CC=14, and TC = 43 (percentage) was calculated. The results of this study show that the types of polymorphisms are a factor for genetic diversity and determine the phenotypic diversity between people, and it may affect the susceptibility of people to diseases and the progression of diseases and polymorphisms. A gene shows a significant relationship with the probability of diabetes. In this study, the possibility of the association of rs7903146 polymorphism with diabetes has been determined, so it can be said that rs7903146 polymorphism can be used as an indicator and marker to detect the susceptibility to diabetes in other research, and considering that this polymorphism Gene Morphism shows a different frequency distribution in different regions, it seems that studying target gene variants in different populations to find their relationship with diabetes is important.