The biological effects of simple tandem repeats: lessons from the repeat expansion diseases.
Tandem repeats are common features of both prokaryote and eukaryote genomes, where they can be found not only in intergenic regions but also in both the noncoding and coding regions of a variety of different genes. The repeat expansion diseases are a group of human genetic disorders caused by long and highly polymorphic tandem repeats. These disorders provide many examples of the effects that such repeats can have on many biological processes. While repeats in the coding sequence can result in the generation of toxic or malfunctioning proteins, noncoding repeats can also have significant effects including the generation of chromosome fragility, the silencing of the genes in which they are located, the modulation of transcription and translation, and the sequestering of proteins involved in processes such as splicing and cell architecture.
Usdin
Karen
K
Section on Gene Structure and Disease, Laboratory of Molecular and Cellular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0830, USA. ku@helix.nih.gov
D000818:Animals; D042622:DNA Repeat Expansion / Q000235:genetics*; D030342:Genetic Diseases, Inborn / Q000235:genetics*; D006801:Humans; D018598:Minisatellite Repeats / Q000235:genetics*; D020080:Tandem Repeat Sequences / Q000235:genetics*