Residents of the District of Columbia lack full democratic representation in the U. S. Senate or the U.S. House of Representatives. Representation in Congress is limited to a non-voting delegate to the House of Representatives and a shadow Senator.
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 personâs entire genetic code. This defect is dominant, meaning that anyone who inherits it from a parent with Huntington's will eventually develop the disease.
Huntington disease-caused by mutations in the HTT gene. The inherited mutation that causes Huntington disease is known as a CAG trinucleotide repeat expansion. This mutation increases the size of the CAG segment in the HTT gene. People with Huntington disease have 36 to more than 120 CAG repeats.