Human endogenous retroviruses and neurological diseases.

The search for a cause of Multiple Sclerosis (MS) and Amyotrophic Lateral Sclerosis (ALS) has remained elusive. A new category of pathogenic components, normally dormant within human genomes, has been identified: Human Endogenous Retroviruses (HERVs). They represent approximately 8% of the human genome and environmental factors have reproducibly been shown to trigger their expression. The resulting production of envelope proteins from HERV-W and HERV-K appear to engage pathophysiological pathways leading to the pathognomonic features of MS and ALS, respectively. These pathogenic HERV elements may thus provide a missing link for the complete understanding of these complex diseases. Moreover, their neutralization may represent a promising strategy to establish novel and more powerful therapeutic approaches.