Interparental Gene Conversion in General Population: A Novel Mechanism For Loss of Heterozygosity

Gene conversion is a process in which genetic material from a donor sequence is unidirectionally copied to an acceptor sequence during the homologous recombination repair of a DNA double-strand break. Although gene conversion has been widely studied in the context of meiosis, hereditary diseases, and cancer development, gene conversion between parental homologs in the zygotes remains controversial. Here, we developed a method to detect interparental gene conversions by focusing on Mendelian errors and identified gene conversion events in one out of every 21.8 births. Some of these events were observed in genetic regions, potentially affecting offspring phenotypes. Interparental gene conversion leads to the offspring inheriting two identical alleles from one parent, resulting in a loss of heterozygosity. Our findings suggest that naturally occurring interparental gene conversions may provide a novel mechanism for the development of certain genetic diseases.