Machado-Joseph Disease (MJD) is an hereditary neuro degenerative condition. It is in a ‘family’ of neurodegenerative diseases that includes Huntington’s Disease. MJD occurs because of a fault in a chromosome that results in the production of an abnormal protein. This protein causes nerve cells to die prematurely in a part of the brain called the cerebellum. The damage to the cerebellum initially causes muscular weakness and progresses over time to a total lack of voluntary control and very significant permanent physical disability.