Medical Genetics

Background: Esophageal, stomach, and colorectal cancers are commonly lethal gastrointestinal tract (GIT) neoplasms, causing almost
two million deaths worldwide each year. some environmental risk factors are acknowledged; however, genetic defects can significantly
contribute to predisposition to GIT cancers. Accordingly, recent works have shown that single-nucleotide polymorphisms (SNPs) within
miRNAs coding sequence (miR-SNPs) and miRNA target sites (target-SNPs) may further contribute to increased risk of developing cancer.
Objectives: In this study, we comprehensively identified miRNA-target gene pairs implicated in GIT cancers and catalogued the presence
of potentially functional miR-SNPs and target-SNPs that impair the correct functional recognition.
Materials and Methods: Using bioinformatics tools, manual literature review, and a highly accurate dataset of experimentally validated
miRNA-target gene interactions, we compiled a list of miRNA-target genes pairs related to GIT cancers and prioritized them into different
groups based on the levels of experimental support. Functional annotations (gene ontology) were applied to these pairs in each group to
gain further information.
Results: We identified 97 pairs in which both miRNAs and target genes were implicated in GIT cancers. Several pairs, denoted as highly
polymorphic pairs, had both miR-SNPs and target-SNPs. In addition, more than 5000 miRNA-target gene pairs were identified in which,
according to the previous reports, either the miRNAs or the target genes had a direct involvement in GIT cancers. More than 800 targetSNPs
are located in regulatory regions that were extracted from the ENCODE project through the RegulomeDB database. Of these, 20 were
classified as expression quantitative trait loci (eQTLs).
Conclusions: Our work provided a comprehensive source of prioritized and annotated candidate polymorphisms inside miRNAs
and their target sites in GIT cancers, which would facilitate the process of choosing right candidate miRNA-target genes and related
polymorphisms for future association or functional studies.
Keywords:MicroRNAs; Gastrointestinal Neoplasms; Colorectal Neoplasms; Gastric Neoplasms; Esophageal Neoplasms; Single
Nucleotide Polymorphisms

Childhood Hepatitis B virus (HBV) infection causes both medical and public health challenges. Infants who acquire HBV parentally have up to 90% risk of developing chronic HBV infection. It is now estimated that approximately 10% of worldwide cancers are attributable to viral infection, with the vast majority (>85 %) occurring in the developing world. In this distribution, elevated rate and prevalence of HBV marker have been found in patients with malignancies as compared to the general population. By reviewing the web-based search for all Persian and English types of scientific peer review published articles initiated using Iran Medex, MEDLINE/PubMed, CINAHL and other pertinent references on websites about HBV and HCV blood disorders. The high prevalence of HBV and HCV infective markers was detected in patients with different malignancies. Moreover, identification of high prevalence of HBV infective markers in leukemia patients proposed strong association between hepatitis viral infections and leukemia.

The present work is aimed at finding variants associated with Type 1 and Type 2 diabetes mellitus (DM) that reside in functionally validated miRNAs binding sites and that can have a functional role in determining diabetes and related pathologies. Using bioinformatics analyses we obtained a database of validated polymorphic miRNA binding sites which has been intersected with genes related to DM or to variants associated and/or in linkage disequilibrium (LD) with it and is reported in genome-wide association studies (GWAS). The workflow we followed allowed us to find variants associated with DM that also reside in functional miRNA binding sites. These data have been demonstrated to have a functional role by impairing the functions of genes implicated in biological processes linked to DM. In conclusion, our work emphasized the importance of SNPs located in miRNA binding sites. The results discussed in this work may constitute the basis of further works aimed at finding functional candidates and variants affecting protein structure and function, transcription factor binding sites, and non-coding epigenetic variants, contributing to widen the knowledge about the pathogenesis of this important disease.