Abstract
MicroRNAs (miRNAs) are known as a new class of small RNAs (18-25 nucleotides) that regulate gene expression at multiple levels from transcription to translation. Considering the important role of miRNAs in cell proliferation, differentiation, and apoptosis, any variations in their expression can contribute to various anomalies, such as tumorigenesis. Single-nucleotide polymorphisms (SNPs) have received much attention as potential genetic markers for diseases due to their advantage of being present at a high frequency in the human genome. SNPs can occur in different parts of the miRNA genes (primary, precursor, and mature) which result in pathological conditions. In this study, recent findings related to the effects of SNPs in miRNAs on their biogenesis and functions and their role in cancer development and progression are discussed. This review was performed using PubMed to search for related reports. The identified effects may be useful for clinical decision-making and providing important new information about the pathophysiology of miRNAs.