The distribution and functional relevance analysis of runs of homozygosity (ROHs) in Chinese Han female population.

Extended homozygosity is a genomic region in which the copies inherited from parents are identical, and has obvious inter-individual differences in length and frequency. Runs of homozygosity (ROHs), regarded as a type of structure variations, may have potential capacity in regulating gene transcription. To learn more about the genome-wide distribution of ROH regions in humans and understand the potential roles, this study applied ROH-based approach to quantify and characterize ROHs in 41 Chinese Han female subjects, and test potential associations between ROHs and mRNA expressions by eQTL analysis to ascertain whether ROHs are relevant to gene transcription in peripheral blood mononuclear cells (PBMCs). 10,884 ROH regions were identified in human genome. The average cumulative length of ROH regions was 217,250 ± 20,241 kb. The number of core segments in each chromosome generally matched the total length of corresponding chromosome, i.e., the longer the chromosome, the more the core segments. Genes located in the core regions of ROH were significantly enriched in multiple basic metabolism pathways. A total of 226 cis-eQTLs and 178 trans-eQTLs were identified. The cis-effect size was mainly concentrated at ± 0.5; and the trans-effect size was mainly concentrated at -1.5 and 1.0. Genes with eQTL effects were significantly enriched in functions related to protein binding, cytosol, nucleoplasm, nuclear membrane, protein binding and citrate metabolic process. This study described comprehensive distributions and characteristics of ROH in Han female Chinese, and recognized the significant role of ROH associated with gene transcription in human PBMC.