Distribution of microRNA Counts Across Human Chromosomes

microRNAs (miRNAs) are a class of non-coding RNAs that play important roles in gene regulation. miRNAs are transcribed from DNA sequences into primary miRNAs and then processed into precursor miRNAs and mature miRNAs. miRNA gene counts in chromosomes for different species have been studied.

Certain chromosomes have higher numbers of miRNA genes in all species, such as the X chromosome, while the Y chromosome has the fewest or no miRNA genes. miRNA counts in different chromosomes might have a positive correlation with coding gene counts in many species. In this study, a regression model was used to find the relationship between the miRNA count and the coding gene count across human chromosomes, and miRNA counts for 23 human chromosomes were predicted based on this regression model. In addition, the chromosome locations for the miRNA biomarkers of major depression, diabetes, Parkinson's disease, and COVID-19 are discussed.

The results reveal that miRNA biomarkers of these diseases are located in various chromosomes. The dispersion of miRNA locations across different chromosomes might explain the complication of the pathology of these diseases. Moreover, diabetes and COVID-19 have the largest number of miRNA biomarkers from Chromosome X.

As Chromosome X is a sex chromosome, this phenomenon may explain the gender difference in the prevalence or severity of diabetes and COVID-19. The significant gender difference in the prevalence or severity of diabetes and COVID-19 might be due to the regulation function of their miRNA biomarkers from Chromosome X.