Two newly discovered genes have been linked to schizophrenia while a gene previously known to be associated with schizophrenia risk has also been linked to autism in a major new study.
Scientists say the findings improve our understanding of brain diseases and could lead to new treatments.
Importantly, this is the first known study to look at the risk of schizophrenia in different groups of people, especially those with African ancestry. It revealed a rare negative variant of the protein gene leads to the risk of schizophrenia in all species.
As with many brain diseases, The causes of schizophrenia are varied and complex, and are often unknown, although it appears that genetic, environmental, and environmental changes in the brain play a role.
“The goal of this study was to better understand how rare genetic variants affect a person’s risk of developing mental illness, particularly mental illness,” said psychiatrist Alexander Charney of the Icahn School of Medicine at Mount Sinai in the US.
Recent studies have shown that people with schizophrenia have more rare protein-truncating variants (PTVs) among ten types of genes than people without schizophrenia. PTVs are changes in the DNA code that can cause a gene to make a protein without essential components, disrupting its function.
However, this study – like most genetic studies – was conducted on Europeans, although schizophrenia is common throughout the world.
In a recent study of two risk genes, SRRM2 and AKAP11, they were identified by comparing the genes of people with schizophrenia and healthy people from different ethnic groups, especially of African ancestry.
The third gene identified in the study, PCLO, has been associated with schizophrenia in the past, but is now known to increase the risk of autism. This adds to what we already know about the genetic association between certain brain conditions.
“It is known that there are parts of genes that are shared between diseases. Clinically, genes can appear differently in the same family. The same difference in one family can cause autism in one family and schizophrenia in another,” says Charney.
“The idea of the same gene having different manifestations is very interesting to us, because it could be useful in helping people in medicine.”
To reach their findings, the team conducted a cross-sectional study of 35,828 cases and 107,877 controls found in previously published data sets.
By combining data from multiple studies that have examined the same phenomenon, meta-analysis can help researchers identify patterns or inconsistencies in the findings of different studies and provide more accurate estimates of effect sizes.
Sequencing whole genomes is expensive, so the researchers used gene-targeted genes carefully selected from this data – from 11,580 people with schizophrenia or schizoaffective disorders, and 10,555 people with no known diagnosis of schizoaffective disorder. mental illness. The people whose genes were included in the study were not closely related, and 40 percent were not European.
“By focusing on a subset of genes, we have found some deleterious variants that may lead to new treatments for schizophrenia,” says lead author, geneticist and research scientist Dongjing Liu from the Icahn School of Medicine at Mount Sinai.
“Also important: by studying people of different races of our ancestors, we found that the genetic variants that cause the risk of schizophrenia to be the same among these different people and that the genetics that were already established in many whites have now spread to non-whites. because of this weak disease .
Schizophrenia is a serious mental illness that affects thinking, perception, and behavior. Usually starting in late adolescence or adulthood and affecting about 7 out of 1,000 people, it shortens a person’s life by about 15 years, according to statistics.
Symptoms include hearing or seeing things that aren’t there, believing things that aren’t real, thinking out of order and acting out of order. These symptoms can be very distressing for the person who has them and for those close to them.
For most people, schizophrenia is managed well with treatment but currently available drugs do not work for everyone, symptoms and side effects vary and more research is needed.
The researchers plan to further investigate the clinical effects of the newly discovered genes on the symptoms or other behaviors of schizophrenia and find treatments that can help them.
Liu and his colleagues conclude that the main contribution of this study to the field of genetics is to show that genetic risk is the same in all species.
“Achieving diversity in population-based research should be critical to preventing health disparities from worsening as findings from genetic research begin to be translated into clinical practice,” they write.
This seems like a promising step in the right direction.
A peer-reviewed study was published in a journal Nature Genetics.