Scientists at the National Institutes of Health discovered that reactivation of ancient viral genes embedded in the human genome may cause the destruction of neurons in some forms of amyotrophic lateral sclerosis (ALS). The results, published in Science Translational Medicine, suggest a link between human endogenous retroviral genes (HERVs) and ALS. The findings also raise the question of whether antiretroviral drugs, similar to those used for suppressing HIV, may help some ALS patients.
For generations, humans have been passing on genetic remnants of HERV infections that may have happened millions of years ago. Although nearly eight percent of the normal human genome is made up of these genes, very little is known about their role in health and disease.