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CAG Repeat Length

Meaning

CAG repeat length refers to the number of times the cytosine-adenine-guanine (CAG) trinucleotide sequence is tandemly repeated within a specific gene’s coding region on the DNA strand. This genetic feature is highly significant in molecular endocrinology and neurology because an abnormal expansion in the number of these repeats can lead to the production of a toxic, elongated protein. Measuring this length is a key diagnostic and prognostic marker for a class of neurodegenerative disorders.