Trinucleotide Repeat Disorder

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A class of clinically heterogenous disorders, defined by the presence of an abnormal and unstable expansion of DNA—triplet repeats—in the mutant gene, with up to 200 copies of the repeated trinucleotide
Examples Hereditary—CAG repeats (Huntington’s disease, Kennedy’s disease), CGG (fragile X syndrome), GCT (myotonic dystrophy, spinal and bulbar muscle atrophy); Acquired—some forms of colourectal CA
References in periodicals archive ?
It is a trinucleotide repeat disorder like Huntington's disease and is caused by excessive numbers of CGG repeats in the promoter region for the FMR1 gene on the X chromosome, which causes the X chromosome to appear broken in this region in certain cell cultures.
FA is now known to be an autosomal recessive trinucleotide repeat disorder, with the most common mutation being an expanded GAA triplet repeat in intron 1 on both alleles of FXN.
Fragile X Syndrome (FXS, OMIM 300624) is a genetic disease inherited through the X chromosome and falling under the umbrella of the trinucleotide repeat disorders.
Testing for FXS and similar trinucleotide repeat disorders (e.
They cover the basic mechanisms of neurodegeneration, Alzheimer's disease and aging, tauopathies, synucleinopathies, trinucleotide repeat disorders, prion disorders, frontotemporal lobal degeneration and amyotrophic lateral sclerosis/motor neuron disease, and other neurodegenerative disorders.
We now understand that it is one of a group of conditions called trinucleotide repeat disorders, and a very brief description of the chemical structure of chromosomes will help to explain how these disorders arise.