Mobile Elements in the Human Genome: Implications for Disease

Abstract

Transposable elements (TEs) are mobile DNA (deoxyribonucleic acid) sequences that represent a great portion of the human genome. TEs are divided into retrotransposons, the more abundant, and DNA transposons, which differ by their structure and transposition mechanisms. The major LINE‐1 and Alu elements represent about one‐third of the human genome and are responsible for several chromosomal rearrangements, gene deletion, insertional mutagenesis as well as RNA (ribonucleic acid) splicing alteration and epigenetic regulation. DNA transposons and human endogenous retroviruses are also a source of genetic alterations. Consequently, TE insertion and mobility lead to human diseases, among which are cancer, hematologic disease, metabolic disease, neurodegenerescence and neurologic and psychiatric diseases. The examples of TE‐related diseases presented herein aim to highlight the interest of increasing our knowledge of TEs through extensive genomic approaches, which may lead to new potential diagnostic markers of diseases. Key Concepts Transposable elements are numerous in the human genome, and the most abundant Alu and LINE‐1 retroelements represent about one‐third of the human genome. Transposable elements are a source of genomic rearrangements that may lead to several human diseases. Gene expression may be affected by transposable elements through the modification of regulatory elements and RNA splicing events. Transposable elements impact and are impacted by epigenetic regulation. Examples of human diseases related to transposable elements include (but are not limited to) cancer, hematologic, metabolic and neurologic diseases.