Scientists have found that ancient DNA lingering in humans are responsible for major psychiatric disorders, such as depression, schizophrenia and bipolar disorder. About eight per cent of human DNA is made up of sequences called Human Endogenous Retroviruses (HERVs), products of ancient viral infections that occurred hundreds of thousands of years ago. So far, the HERVs were seen as ‘junk DNA’ with no purpose, but the new study by researchers from King’s College London sees them in a new light, offering to revolutionise mental health treatment.
A detailed publication of the research can be found in Nature Communications.
Its foundation is the examination of extensive research involving tens of thousands of participants, both with and without mental health issues. This was combined by the team with data from 800 autopsied brain samples.
“Our results suggest that these viral sequences probably play a more important role in the human brain than originally thought, with specific HERV expression profiles being associated with an increased susceptibility for some psychiatric disorders,” Dr Timothy Powell, co-senior author, told The Evening Standard.
Dr. Douglas Nixon, a co-senior author, told “We think that a better understanding of these ancient viruses, and the known genes implicated in psychiatric disorders, have the potential to revolutionise mental health research and lead to novel ways to treat or diagnose these conditions.”
But Dr. Nixon also stated that more investigation is required to determine the precise role of the majority of HERVs.
Over six billion individual DNA letters are distributed among 23 pairs of chromosomes to make up the human genome. Scientists fragment the DNA during analysis and subsequently sequence it.
The sequencing machines present individual letters in each piece and scientists try to assemble the pieces in the right order.
