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.
Humans have 46 chromosomes (23 pairs). The faulty gene that causes Huntington's disease is found on chromosome number four. The normal copy of the gene produces a protein called huntingtin, but the faulty gene contains an abnormal region of what are called CAG repeats. This area is larger than normal and produces a mutant form of huntingtin.