DNA is the genetic code that is the base for who we are. From eye color, and height, to if you like spicy food, our genetics have influence over who we are. Psychiatric disorders such as schizophrenia, bipolar disorder, major depressive disorder, attention deficit hyperactivity disorder, and autism spectrum conditions also have been known to have a large genetic component.
King’s College London led a study looking at about eight percent of the Human genome called Human Endogenous Retroviruses (HERVs). HERVs are a remnant of ancient viral infections that occurred hundreds of thousands of years ago, which until recently were thought to be “ junk DNA”. The study examined data from genetic studies that include tens of thousands of people, both with and without mental health conditions and information from autopsy brain samples from 800 individuals, to take a look at how DNA variations linked to psychiatric disorders affect the expression of HERVs.
While most genetic risk variants associated with psychiatric diagnoses affect genes with established biological functions, the study identifies certain genetic risk variants that specifically impact HERV expression. The study identified five robust HERVs expression signatures associated with psychiatric disorders, including two HERVs linked to schizophrenia risk, one associated with both bipolar disorder and schizophrenia, and one associated with depression risk.
Dr. Rodrigo Duarte, first author and Research Fellow at the IoPPN, King’s College London, highlights the study’s findings, acknowledging the substantial genetic contribution to psychiatric disorders. Although the exact mechanism through which HERVs influence brain cells remains unclear, the study suggests that their regulation of expression is crucial for brain function.
Co-senior author Dr. Douglas Nixon from the Feinstein Institutes for Medical Research at Northwell Health, US, emphasizes the need for further research to understand the exact function of HERVs identified in the study. He suggests that a deeper understanding of these ancient viruses, alongside known genes implicated in psychiatric disorders, could revolutionize mental health research and pave the way for novel treatment and diagnostic approaches.
