Viral DNA in humans linked to psychiatric disorders
Ancient viral DNA sequences expressed in brain linked to psychiatric disorder susceptibility, including schizophrenia, bipolar disorder, and depression.
A Depressed young man with blurred head in dark room. Depression, among others, have been linked to viral DNA embedded in human brains over hundreds of thousands of years ago.
Image credit: Vijay Sadasivuni
- Thousands of DNA sequences from ancient viral infections are expressed in the brain.
- These sequences, called Human Endogenous Retroviruses (HERVs), contribute to susceptibility for psychiatric disorders such as schizophrenia, bipolar disorder, and depression.
- HERVs make up about 8% of our genome and were previously thought to be “junk DNA” with no important function.
- The study used data from large genetic studies involving tens of thousands of people, both with and without mental health conditions, to explore how DNA variations linked to psychiatric disorders affect the expression of HERVs.
- Five robust HERV expression signatures were associated with psychiatric disorders, including two HERVs associated with risk for schizophrenia, one associated with risk for both bipolar disorder and schizophrenia, and one associated with risk for depression.
- The study suggests that regulation of HERV expression is important for brain function.
Source: King's College London