Mental illnesses are thought to directly impact about one in every seven people worldwide, according to the World Health Organization, and those around them are also often affected. Mental health issues can be very difficult to treat, in part because the causes are still unclear and can be due to a complex mix of influences that include environmental factors, genetics, and lifestyle choices. But researchers have now identified a single gene that has the potential to lead to mental health problems. The findings have been reported in Molecular Psychiatry.
"Our current findings indicate that GRIN2A is the first known gene that, on its own, can cause a mental illness. This distinguishes it from the polygenic causes of such disorders that have been assumed to date," noted first study author Professor Johannes Lemke, the Director of the Institute of Human Genetics at the University of Leipzig Medical Center.
In this study, the investigators analyzed health and genetic data from 121 different people, and found that changes in the sequences of a gene known as GRIN2A were linked to many mental health disorders, including schizophrenia. People who carried GRIN2A variants developed their mental health problems early in life as well, as opposed to many others who tend to get them later.
“What is striking is that, in the context of a GRIN2A alteration, these disorders already appear in childhood or adolescence, in contrast to the more typical manifestation in adulthood," explained Lemke.
Previous research has linked variations in GRIN2A to epilepsy or intellectual disability, but the individuals who carried GRIN2A variants that were analyzed in this study only had psychiatric symptoms.
GRIN2A normally generates a protein that can influence electrical signaling in neurons, which helps to control neuronal activity. Variations in GRIN2A were found to change how a molecule called the NMDA receptor functioned. This receptor can be critical to neuronal communication in the brain.
The investigators also determined that when patients were given a dietary supplement called L-serine, which activated the NMDA receptor, there was a noticeable improvements in their psychiatric symptoms.
Sources: Universität Leipzig, Molecular Psychiatry
