miRNAs differentially expressed by next-generation sequencing in cord blood buffy coat samples of boys and girls.

AIM Differences in children's development and susceptibility to diseases and exposures have been observed by sex, yet human studies of sex differences in miRNAs are limited. MATERIALS & METHODS The genome-wide miRNA expression was characterized by sequencing-based EdgeSeq assay in cord blood buffy coats from 89 newborns, and 564 miRNAs were further analyzed. RESULTS Differential expression of most miRNAs was higher in boys. Neurodevelopment, RNA metabolism and metabolic ontology terms were enriched among miRNA targets. The majority of upregulated miRNAs (86%) validated by nCounter maintained positive-fold change values; however, only 21% reached statistical significance by false discovery rate. CONCLUSION Accounting for host factors like sex may improve the sensitivity of epigenetic analyses for epidemiological studies in early childhood.