triplet repeat expansion
Quick Summary
Triplet repeat expansion is a type of genetic mutation where a specific sequence of three DNA bases repeats more times than usual within or near a gene. This expansion can lead to various genetic disorders, such as Huntington disease and fragile-X syndrome.1
These disorders often exhibit a pattern called anticipation, where the condition becomes more frequent and severe in subsequent generations. The repeat length increases as it's passed down, leading to greater instability until a full expansion mutation occurs. These conditions are a form of single-gene non-Mendelian inheritance.12
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