Study says that a gene adapted from archaic hominins may increase mental health risk in modern humans

A recent study suggests that genetic adaptations inherited from ancient humans living tens of thousands of years ago might increase the susceptibility of modern humans to mental health issues, such as depression.

The study, published in PLOS Genetics, indicates that modern humans have inherited a portion of their genetic makeup from Denisovans, which makes them more prone to mental health problems.

Spanish researchers built on a previous study that focused on a variant of the SLC30A9 gene, suggesting that it might have evolved through positive selection, particularly in East Asian populations.

This gene is responsible for regulating zinc transport across cell membranes in the body. Zinc plays a vital role in the healthy development and function of the nervous and immune systems, as well as maintaining the excitability of the nervous system, which has a connection to mental health.

However, the adaptation of these genes in modern humans seems to alter this regulation. Although previous studies have also hinted at the association of the SLC30A9 genetic variant with a higher risk of depression and mental health issues, researchers have not made definitive claims regarding these connections.

Rubén Vicente, a molecular biologist from Pompeu Fabra University, suggests that expanding the study to animal models in the future could provide insights into this predisposition to mental illnesses.

The gene did not match with Neanderthals, but when closely compared with the Denisovan gene, a match for the SLC30A9 gene emerged.

According to Ana Roca-Umbert, an evolutionary biologist from Pompeu Fabra University, genomic analysis revealed that this genetic variant likely originated from interbreeding with archaic humans in the past, possibly the Denisovans.

The research team conducted lab experiments that demonstrated how the genetic variation was linked to differences in cellular structure, including mitochondria, and how it regulated zinc, thereby influencing metabolism.

The researchers also suspect that the Denisovan variant may have provided protection against cold climates. Jorge Garcia-Calleja, another evolutionary biologist, suggests that “the change was beneficial and proved a selective advantage for humans,” which is why the SLC30A9 variant is present in the current population.

The study highlights the ongoing exploration of how our genes evolve and affect our health, and while there is much more to learn in this field, this study reveals significant genetic links to our past.