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. Definition. Huntington's disease is an inherited disease that causes the progressive breakdown (degeneration) of nerve cells in the brain. Huntington's disease has a broad impact on a person's functional abilities and usually results in movement, thinking (cognitive) and psychiatric disorders.
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.