What genetic condition is Huntington's disease categorized as?

Huntington's disease is categorized as an autosomal dominant disorder because it is caused by mutations in a single gene located on one of the autosomes (non-sex chromosomes). In this case, the gene involved is the HTT gene, which produces the huntingtin protein. The autosomal dominant nature of the disorder means that an individual only needs to inherit one mutated copy of the gene from one parent to develop the disease. This results in a 50% chance of passing the mutated gene to offspring. The symptoms of Huntington's typically emerge in mid-adulthood, and they include progressive motor dysfunction, cognitive decline, and psychiatric issues.

Understanding this classification is crucial, as it distinguishes Huntington's disease from conditions that require two mutated copies (one from each parent) to manifest, like autosomal recessive disorders, or from those linked to sex chromosomes, which are referred to as X-linked disorders. Chromosomal disorders typically involve abnormalities in chromosome number or structure rather than single-gene mutations like those seen in Huntington's disease.