what is a defective gene
Huntington's disease is a progressive brain disorder caused by a single defective gene on chromosome 4 â one of the 23 human chromosomes that carry a personâs entire genetic code. This defect is dominant, meaning that anyone who inherits it from a parent with Huntington's will eventually develop the disease.The disorder is named for George Huntington, the physician who first described it in the late 1800s.his defect is dominant, meaning that anyone who inherits it from a parent with Huntington's will eventually develop the disease. The disorder is named for George Huntington, the physician who first described it in the late 1800s.