28th February 2024

Trinucleotide repeats and anticipation

Anticipation is a phenomenon seen with some autosomal dominant conditions whereby the condition affects the younger generation at an earlier age with increased severity. This often occurs in diseases caused by trinucleotide repeats, such as Huntington’s disease, myotonic dystrophy, spinocerebellar ataxia and Fragile X syndrome.

The inherently unstable nature of the trinucleotide repeat allows expansion to occur during meiosis, which has been linked to increased severity of the condition between generations.