Huntington's disease is caused by an expanded trinucleotide repeat mutation of cytosine-adenine-guanine (CAG) in the HTT gene located on chromosome 4 (4p16.3). This mutation leads to an abnormally long stretch of glutamine in the huntingtin protein. Normal individuals have about 10 to 35 CAG repeats, while people with Huntington's disease have 40 or more. Those with 36-39 repeats may show reduced penetrance, meaning symptoms may appear later or not at all. The unstable mutation is unstable may expand further when passed to offspring, a process called anticipation, often resulting in earlier onset in the next generation (Walker, 2007; Ross et al., 2014). can you rewrite it