Familial dysautonomia

Familial dysautonomia FD is one example of a group of disorders known as hereditary sensory and autonomic neuropathies HSAN. All HSAN are characterized by widespread sensory dysfunction and variable autonomic dysfunction caused by incomplete development of sensory and autonomic neurons. The disorders are believed to be genetically distinct from each other. Unlike the other HSAN, FD has been noted only in individuals of Ashkenazi Jewish extraction and so it is included as one of the Jewish genetic diseases.

Individuals affected with FD are incapable of producing overflow tears with emotional crying. Frequent manifestations of FD include inappropriate perception of heat, pain, and taste, as well as, labile blood pressures and gastrointestinal dysmotility. Other problems experienced by individuals with FD include excessive sweating, dysphagia and vomiting, aspiration and frequent pneumonia, speech and motor incoordination, labile blood pressures (episodic hypertension and postural hypotension), poor growth and scoliosis. Yet affected individuals usually are of normal intelligence. FD patients can be expected to function independently if treatment is begun early and major disabilities avoided.