Familial dysautonomia is an inherited disorder that affects the nervous system. People with this disorder are born with fewer nerve fibers to send signals throughout the body. They also have a lower level of a chemical called norepinephrine which is responsible for sending messages between nerves. As a result, these individuals have trouble with many important bodily functions such as digestion, urination and control of blood pressure. The disease occurs when a copy of the IKBKAP gene is passed from the mother and father to the child. The disease is most common in individuals who are Jewish from eastern European descent (Ashkenazi). It is estimated that 1 in 3600 of these individuals will have this disorder.