Trinucleotide repeat disorder

Genetic disorders due to increases in the number of repeating nucleotides Medical conditionTrinucleotide repeat disorderOther namesTrinucleotide repeat expansion disorders, Triplet repeat expansion disorders or Codon reiteration disorders In genetics, trinucleotide repeat disorders, a subset of microsatellite expansion diseases (also known as repeat expansion disorders), are a set of over 30 genetic disorders caused by trinucleotide repeat expansion, a kind of mutation in which repeats of three nucleotides (trinucleotide repeats) increase in copy numbers until they cross a threshold above which they cause developmental, neurological or neuromuscular disorders. In addition to the expansions of these trinucleotide repeats, expansions of one tetranucleotide (CCTG), five pentanucleotide (ATTCT, TGGAA, TTTTA, TTTCA, and AAGGG), three hexanucleotide (GGCCTG, CCCTCT, and GGGGCC), and one dodecanucleotide (CCCCGCCCCGCG) repeat cause 13 other diseases. Depending on its location, the unstable trinucleotide repeat may cause defects in a protein encoded by a gene; change the regulation of gene expression; produce a toxic RNA, or lead to production of a toxic protein. In general, the larger the