King's College London

The study, conducted by researchers from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London and Northwell Health, focused on human endogenous retroviruses (HERVs)—remnants of ancient retroviral infections that are now fixed features within our DNA. Using a cutting-edge genomic technique, the team identified specific HERV expression signatures linked to multiple sclerosis and amyotrophic lateral sclerosis (also known as motor neurone disease). These findings suggest that viral elements within our DNA may play a role in the development of these neurodegenerative diseases.

Neurodegenerative diseases are characterised by progressive degeneration and loss of neurons, resulting in the deterioration of the nervous system’s structure and function. Multiple sclerosis is amongst the most common neurodegenerative diseases affecting young adults, with over 150,000 people in the UK living with this lifelong condition. Amyotrophic lateral sclerosis is less common, with approximately 5,000 cases in the UK, and it is associated with a more severe prognosis.

Understanding genetic architecture of neurodegenerative diseases

Published in Brain, Behavior, and Immunity, the study marks an important advance in understanding the complex genetic architecture of neurodegenerative diseases. While previous studies hinted at a connection between HERVs and these conditions, this is amongst the first to pinpoint specific HERVs that are associated with disease susceptibility.

The researchers analysed data from hundreds of brain samples to map out the relationship between HERV expression and genetic risk factors for four neurodegenerative diseases, including Parkinson’s disease, Alzheimer’s disease, amyotrophic lateral sclerosis and multiple sclerosis. They identified a robust HERV signature on chromosome 12q14 (MER61_12q14.2) associated with amyotrophic lateral sclerosis, and another on chromosome 1p36 (ERVLE_1p36.32a), associated with multiple sclerosis. These viral sequences appear to be involved in homophilic cell adhesion—a process essential for communication between cells in the brain. No robust signatures were observed for Alzheimer’s and Parkinson’s disease, although the authors highlight that larger studies may uncover novel associations in the future.

Implications for Future Treatments

As the global burden of neurodegenerative diseases continues to grow—with over 50 million people currently affected worldwide, a number projected to nearly triple by 2050—these insights offer a promising direction for future research and treatment development. This discovery opens up new possibilities for therapeutic interventions targeting HERVs. By better understanding how these viral elements drive disease, researchers hope this could aid the development of novel treatments that could mitigate the impact of neurodegenerative diseases.

The research was part-funded by the National Institute for Health and Care (NIHR) Maudsley Biomedical Research Centre, the National Institutes of Health (NIH), and The Psychiatry Research Trust.

'Ancient viral DNA in the human genome linked to neurodegenerative diseases' (Rodrigo Duarte, Douglas Nixon, Timothy Powell) was published in Brain, Behavior, and Immunity. DOI: 10.1016/j.bbi.2024.10.020.

 For more information, please contact Franca Davenport, Senior Communications and Engagement Manager (part-time), NIHR Maudsley Biomedical Research Centre.