Huntington's disease is inherited in which pattern?

• A. Autosomal recessive
• B. X-linked
• C. Autosomal dominant
• D. Mitochondrial

Answer: (C)

Huntington’s disease follows an autosomal dominant inheritance pattern. That means a single mutated copy of the HTT gene is enough to cause the disease, so an affected person has a 50% chance of passing it to each child, regardless of sex. This leads to vertical transmission across generations. The underlying mutation is a CAG trinucleotide repeat expansion, and greater repeat length can cause earlier onset in future generations—a phenomenon called anticipation, especially when the mutation is passed from father. This pattern differs from autosomal recessive conditions (which require two mutated copies), X-linked conditions (which follow a different transmission route and often affect males more), and mitochondrial inheritance (passed only from the mother through mitochondrial DNA).