HERVs, transposons and human diseases : part I

Abstract

It has been found that the human genome is full of relic retroviral DNA sequences called HERVs (Human Endogenous RetroViruses). A HERV is a type of a transposon, the latter being a piece of DNA sequence that can move from one position to another position in the genome, hence its other name of ‘jumping gene’. HERVs and other transposons are held in check from doing havoc in the genome by several mechanisms, one of which is epigenetic in nature (namely DNA methylation and histone modifications). HERVs and other transposons are being implicated to have physiological and pathological functions in the genomes of the cells that host them. Accumulating evidence is showing that they may be associated with certain human diseases, specifically in some autoimmune diseases (e.g. rheumatoid arthritis, psoriasis, systemic lupus erythematosus, insulin-dependent diabetes mellitus), neurological diseases (e.g. schizophrenia, multiple sclerosis, motor neuron disease) and cancer. Understanding how these relic viruses and other jumping genes bring about these human diseases could help in their prevention and treatment.