A recent genetic study suggests that some parents may be more likely to have daughters than sons due to subtle differences in their DNA. Researchers have identified a gene variant, rs144724107, that increases the likelihood of having a daughter by 10%. This means that individuals with this gene variant have a 60% chance of having a daughter in a given pregnancy, rather than the expected 50% chance.
The rs144724107 variant is located near a gene family called ADAMTS, which is involved in sperm production and fertilization. It is still unclear whether this gene variant needs to be carried by the mother, father, or both to influence the offspring’s sex ratio. The findings of this study, published in Proceedings of the Royal Society B: Biological Sciences, support the classic evolutionary biology theory known as Fisher’s principle, which suggests that sexually reproducing organisms typically produce equal numbers of male and female offspring.
To detect this gene variant, researchers analyzed the genomes of 450,000 individuals in the U.K. Biobank database. While only 0.5% of participants carried the rs144724107 variant, researchers suspect that there may be other variants that similarly influence offspring sex. The study found that the sex ratio at the population level remains around 0.5, but more research is needed to confirm these findings in other populations and to identify additional gene variants that affect offspring sex.
In a separate analysis, the researchers could not find the rs144724107 variant in the genomes of 14,500 postmenopausal women in the U.S. Women’s Health Initiative dataset. This highlights the need for further research in more diverse populations. The study was limited to individuals of European ancestry, so it is essential to investigate whether similar variants exist in other ethnic groups.
Overall, this study provides valuable insights into the genetic factors that may influence the sex of offspring. Further research is needed to confirm these findings and explore the implications of genetic variants on offspring sex ratios in different populations.