CGG repeat expansion

CGG repeat expansion refers to a genetic mutation where a specific sequence of DNA, consisting of three nucleotides "CGG," is repeated excessively. This occurs in certain genes, notably the FMR1 gene, and can lead to disorders like Fragile X syndrome, which affects intellectual development. Normally, the CGG sequence is repeated a limited number of times, but when it expands beyond a certain threshold, it disrupts normal gene function. This can result in symptoms such as cognitive impairment and emotional difficulties, making it a significant focus in genetic research and counseling.