How does a person inherit this genetic disorder? Is it dominant or recessive? Is it genetic or chromosomal?

Huntington's Disease is a genetic disease that is passed from parent to child by a mutation. It occurs when a small sequence of DNA on chromosome 4 has several base pairs that are repeated many times.The normal gene has 3 DNA bases which all contain the sequence CAG. People with Huntington's Disease have this sequence repeating dozens of times. Over time in each successive generation, this sequence repeats itself even more. Huntington's Disease is autosomal dominant so only one copy of the defective gene is necessary to be passed down from the parent to child to inflict the child with the disease.