What type of inheritance pattern does Huntington's disease exhibit?

Huntington's disease exhibits autosomal dominant inheritance, which means that only one copy of the mutated gene, located on an autosome (non-sex chromosome), is sufficient to cause the disorder. This pattern of inheritance allows affected individuals to pass the mutated gene to their offspring with a 50% chance, regardless of the gender of the parent or child.

The gene responsible for Huntington's disease codes for a protein called huntingtin, and the mutation involves an expansion of CAG repeats within the gene. As a result, individuals with the mutation experience progressive neurodegeneration, leading to various neurological symptoms. Because the disorder manifests in adulthood, it's often observed that an affected parent can have children who inherit the condition, showcasing the autosomal dominant pattern.

The other inheritance patterns do not apply to Huntington's disease: autosomal recessive requires two copies of the mutated gene to exhibit the disease; sex-linked inheritance refers to traits associated with genes on sex chromosomes; and mitochondrial inheritance involves genes passed from mothers to their offspring via the mitochondria, which is not the case with Huntington's disease.