Familial dysautonomia (FD) ; also known as Riley-Day syndrome and autonomic neuropathy type III, is a genetic disorder that affects the development and survival of certain nerve cells and causes sensory and autonomic dysfunction. The autonomic nervous system controls involuntary actions such as digestion, breathing, production of tears and the regulation of blood pressure and body temperature. It also affects the sensory nervous system, which controls activities related to the senses, such as taste and the perception of pain, heat and cold.
