Introduction: Diabetes mellitus is a chronic metabolic disorder characterized by elevated blood glucose levels. Over the past two decades, the prevalence of diabetes has been increasing rapidly in Mongolia. Although the national prevalence is not the highest in the region, it is relatively comparable to that of other Asian countries such as South Korea (6.8%) and Japan (6.6%) among adults aged 20 to 79. Type 2 diabetes mellitus (T2DM) is known to be strongly influenced by genetic factors, and in recent years, significant research has focused on identifying associated genetic variants. Among the numerous genes linked to T2DM, the TCF7L2 gene has been extensively studied. TCF7L2 (Transcription Factor 7-Like 2) is located on the short arm of chromosome 10 at locus q25.2 25.3. It consists of 19 exons and encodes a protein comprising 619 amino acids. As a transcription factor, TCF7L2 plays a critical regulatory role in various processes, including pancreatic β-cell function, insulin secretion, insulin receptor activity, and multiple intracellular biochemical signaling pathways. Objectives of the study: Genomic DNA was extracted from the blood samples of individuals diagnosed with type 2 diabetes mellitus (ICD-10 code: E11), and a specific region of the TCF7L2 gene was amplified and detected using PCR. Reasearch materials and methods: This study employed an experimental research design and used purposive sampling to recruit 30 participants who had been diagnosed with type 2 diabetes mellitus (ICD-10: E11). A total of 5–10 mL of peripheral blood was collected from each participant in EDTA-containing tubes. Genomic DNA (gDNA) was extracted from 30 samples, and the DNA yield was quantified using a NanoDrop spectrophotometer. The extracted gDNA was then used as a template for the amplification of an 888 base pair (bp) fragment of the TCF7L2 gene using polymerase chain reaction (PCR). The PCR products were verified by gel electrophoresis, confirming the presence of the expected 888 bp amplicon. Conclusion Blood samples from 30 individuals diagnosed with type 2 diabetes mellitus (T2DM) were analyzed. The extracted DNA showed a purity range of 1.73 to 2.1 (A260/A280), indicating that the samples met the general quality requirements for PCR. DNA concentrations measured using a NanoDrop spectrophotometer ranged from 12.7 to 54.3 ng/µl, which is sufficient for downstream PCR analysis. The TCF7L2 gene, known to be associated with the development of T2DM, was detected in 26% of the total samples.

Background: Nucleic acid sequencing is a multi-step process taken place in medical research or diagnostic laboratories. Since the emerge of second generation sequencing technology generally referred as next generation sequencing (NGS), the mass parallel reads covering human genome or transcriptome is achieved by cost cut down over thousand folds. Though the technology made tremendous push forward to various applications, its data analysis time and effort still takes worrisome time and human effort, bringing the emerge of next-step demand: targeted mass sequencing of only desired part from human genome or transcriptome with lower material cost and labor. By targeted sequencing, both run cost and data analysis process can be further cut down, and the read results are more reliable on changes such as determining varied number of repeats, heterozygote alleles, deletions, chromosomal scale abnormality and more. Objective: In this study, we explored the utilization of biotinylated RNA baits on captured sequencing of cancer marker genes functional regions. Method: Targeted NGS was achieved by capturing desired genomic regions using preparatory nucleic acid probes. RNA bait capturing of desired genomic regions has shown to have high specificity and quality.
The study was carried out with informed consent obtained from patients, with the approval №53 in 2018.03.15 by Medical Ethics committee, Ministry of Health, Mongolia. Result: By preparing library of biotinylated RNA baits with 75000 unique sequences, we achieved mass parallel sequencing of human 410 cancer-marker-genes’ exons and UTRs with average read depth ~760, and covered thousands of SNPs on 5 genomic DNA samples. Tissue samples derived from breast cancer and ovary cancer had SNP and deletion on 7 marker genes (BRCA1, BRCA2, ATM, BRIP1, PTEN, TP53, RAD51C) not registered in database. Conclusion Experiments showed RNA baits with up to 117 nucleotide length, produced from ssDNA oligonucleotide stock, can be utilized to capture desired regions of human genome, and bring the cost of captured mass sequencing to 1500 USD, with 93.14-93.33% of Q30 read quality.