Analysis of Genetic Polymorphism in TCF7L2 Causing Diabetes

Author Name(s): *Sravanthi Anumandla, Sushma Rayabarapu
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The current Day research in the area of Medical molecular Biology and Diagnostics indispensably utilises the principles and applications of Bioinformatics tools and software’s so as to complete the task accurately within a short span of time. In the present study the Genetic Polymorphism in the gene TCF7L2 of humans. Responsible for causing diabetes has been analysed using various insilico methodologies. The blood samples of the diabetic and control were collected and the genomic DNA extraction was performed. The Sequence of the gene TCF7L2 was retrieved from NCBI data base and a primer was designed for its amplification using Primer 3 Software. The standard primer is than synthesized and used for PCR amplification of the samples. The amplified products were then sent for sequencing. The results obtained after sequencing was further analysed using insilico tools and the polymorphism can be detected among the samples after multiple sequence alignment. The SNP position of TCF7L2 has been obtained from SNP database of NCBI.


TCF 712, Polymorphism, SNP, MSA, PCR, Amplification etc


Diabetes mellitus (DM), commonly referred to as diabetes, is a group of metabolic diseases in which there are high blood sugars levels over a prolonged period. Symptoms of high blood sugar include frequent urination, increased thirst, and increased hunger. If left untreated, diabetes can cause many complications.

Type 1 diabetes mellitus is characterized by loss of the insulin-producing beta cells of the islets of Langerhans   in the pancreas, leading to insulin deficiency. This type can be further classified as immune-mediated or idiopathic. The majority of type 1 diabetes is of the immune-mediated nature, in which a T-cell mediated autoimmune attack leads to the loss of beta cells and thus insulin. It causes approximately 10% of diabetes mellitus cases in North America and Europe. Most affected people are otherwise healthy and of a healthy weight when onset occurs. Type 2 DM is characterized by insulin resistance, which may be combined with relatively reduced insulin secretion. The defective responsiveness of body tissues to insulin is believed to involve the insulin receptor. However, the specific defects are not known. Diabetes mellitus cases due to a known defect are classified separately. Type 2 DM is the most common type of diabetes mellitus. “Secondary” diabetes refers to elevated blood sugar levels from another medical condition. Secondary diabetes may develop when the pancreatic tissue responsible for the production of insulin is destroyed by disease, such as chronic pancreatitis (inflammation of the pancreas by toxins like excessive alcohol), trauma, or surgical removal of the pancreas.

Some of the symptoms of Diabetes include:

  • Increased appetite:Diabetics are unable to utilize glucose for energy so they keep feeling hungry all the time since the cells are craving for glucose.
  • Increased thirst:Increased blood sugar can make diabetics dehydrated, inducing thirst all the time.
  • Frequent urination:Dehydration along with the constant feeling of thirst, diabetics tend to drink more water which is the reason they end up visiting the bathroom more often. Excess urination is a common sign of diabetes.
  • Suddenweight loss: In diabetics, despite the intake of glucose, the body isn’t able to utilize it for deriving energy. Therefore, the body utilizes fat to derive energy, causing weight loss, without exercising and dietary changes.
  • Poor wound healing:Increased blood sugar causes hardening of blood vessels affecting blood circulation. When blood flow to injured tissues gets affected, blood clotting proteins and other factors that promote healing do not reach the site of injury. This causes wounds to heal slowly.


The aim of the current research was to analyse the Single Nucleotide polymorphism among the disease and the normal samples of Diabetic individuals with respect to the gene TCF7L2 and the SNP C/ T. The gene sequence of the same was retrieved from NCBI and the SNP was selected from SNP database. Primer3 tool has been employed to design the primer for amplification of the selected gene region containing the SNP. The DNA samples were than amplified with the specific primers using PCR. The amplicons were sent for ABI sequencing. The sequences obtained were further compared using texshade tool of SDSC Biology workbench. The results showed that only 4 samples of 10 disease showed the presence of SNP C/T at the location and all the others including the normal showed the wild allele. This indicates that the presence of SNP leads to diabetes, however all diabetic cases are not only due to the presence of SNP. This study can further be extended to develop a prognostic or diagnostic approach for the early detection of diabetic condition based n sequencing.

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