Huntington's disease DNA and the HTT gene
Update: Population-scale repeat expansions elucidate disease risk and brain atrophy https://www.nature.com/articles/s41586-026-10345-6 Huntington's disease is an autosomal dominant disorder, meaning a person needs only one copy of the nontypical gene to develop the disorder. DNA about the HTT gene, which typically has 40 to 50 CAG repeats. Huntington's disease is a genetic disorder caused by mutations in the HTT gene. This gene is located on chromosome 4 and is responsible for producing a protein called huntingtin. The key feature of the mutation in Huntington's disease is the expansion of a specific DNA sequence known as a CAG repeat. In the HTT gene, CAG repeats normally range from about 10 to 35 in the general population. However, in individuals with Huntington's disease, this sequence is abnormally expanded, typically to 40 to 50 repeats, although it can be even higher. This expanded repeat results in the production of an altered form of the huntingtin protein, w...