repeat expansion mutation

Repeat expansion mutations occur when specific sequences of DNA, called repeats, are copied more times than normal. These extra repeats can disrupt how genes function, leading to health issues. For example, a gene might normally have 10 repeats of a sequence, but in a mutation, it might have hundreds. This abnormal increase can cause proteins to malfunction or buildup, resulting in diseases such as Huntington’s disease or fragile X syndrome. These mutations are often heritable and can worsen or become more severe across generations.