The Five Senses and Beyond: The Encyclopedia of Perception - Jennifer L. Hellier 2017

Familial Dysautonomia

Familial dysautonomia, also called hereditary sensory and autonomic neuropathy, type III and also known as Riley-Day syndrome, is a genetic disorder that affects the development and survival of certain nerve cells. It disturbs cells in the autonomic nervous system, which is responsible for things including but not limited to digestion, breathing, tear production, and the regulation of blood pressure and body temperature. Familial dysautonomia also affects the sensory nervous system, particularly those responsible for the sense of taste, the perception of pain, and the perceptions of heat and cold. Thus, persons with familial dysautonomia often have a form of congenital insensitivity to pain. Familial dysautonomia affects about 1 in every 3,700 individuals and is primarily found in central or eastern European Jewish populations. It is extremely rare in the general population.

Familial dysautonomia is an autonomic recessive disease, meaning both copies of the gene in each cell must have the mutation. Parents are called “carriers” for the disorder, as the mother and father carry one copy of the affected gene. Carriers typically do not have any of the signs of the disease. As of now, the average life expectancy for an individual with familial dysautonomia is age 20, with about 60 percent of the population with the disorder surviving to that age.

Signs and Symptoms

The first signs and symptoms of familial dysautonomia are most often seen within the first few months of birth. Early signs and symptoms include but are not limited to feeding difficulties, poor growth, lack of tear production, and difficulty maintaining body temperature. Older infants are likely to hold their breath for prolonged periods of time, causing a bluish appearance of the skin (cyanosis) or fainting. This behavior will typically stop by the age of six years old. Normal developmental milestones are usually delayed; however, some children with familial dysautonomia may develop on time and not show any signs of delay.

In school-aged children, symptoms may include bed-wetting, poor balance, and poor bone quality. Additionally these children may have kidney and heart problems. They could experience orthostatic hypotension—which is a drop in blood pressure upon standing—and could have episodes of high blood pressure when they get nervous or excited. About 33 percent of children with familial dysautonomia experience learning disabilities, such as having a short attention span.

By adulthood, most symptoms of familiar dysautonomia have been overcome except for balance and walking difficulties. Thus, adults may need assistance for balance and/or walking. As a person with familiar dyautonomia ages, he or she may experience frequent lung infections and worsening of vision because the optic nerves shrink.

Treatment and Management

As of today, there is no cure for familial dysautonomia. The only treatment is supportive and preventive care. These treatments include but are not limited to medications to maintain the cardiovascular, respiratory, and digestive functions, and surgical interventions such as (1) placing a gastrostomy feeding tube into the stomach to reduce aspiration of food, which can cause lung infections; (2) fusing spinal vertebrae together to provide more stability for the person when walking; and (3) cauterizing the tear ducts so that the tears produced by the eye stay on the eye longer and do not drain away. Finally, persons with familial dyautonomia may have therapy to help with speech development.

Research

At the Dysautonomia Center at the New York University School of Medicine, there is a state of the art clinical research lab that is fully equipped to perform neurophysiological tests of sensory and autonomic nerve functions. The Dysautonomia Foundation funds this center as it is the only treatment and clinical research center in the world. Past clinical research has led to the development of new treatments, which have altered the prognosis of the disease as well as enhanced the quality of life for individuals with the disease. Started in 1990, genetic research focused on identifying the familial dysautonomia gene with a goal of developing a treatment and cure. Trials using kinetin are currently under way at the Dysautonomia Center in patients with familial dysautonomia thanks to the research of Drs. James Gusella and Susan Slaugenhaupt when they identified the gene with the mutation in 2001.

Renee Johnson

See also: Autonomic Nervous System; Congenital Insensitivity to Pain; Somatosensory System

Further Reading

Dysautonomia Foundation. (n.d.). Dysautonomia Foundation Research. Retrieved from http://www.familialdysautonomia.org/facts.htm

Dysautonomia Foundation. (n.d.). FD Fact Sheet. Retrieved from http://www.familialdysautonomia.org/facts.htm

Palma, Jose-Alberto, Lucy Norcliffe-Kaufmann, Cristina Fuente-Mora, Leila Percival, Carlos Mendoza-Santiesteban, & Horacio Kaufmann. (2014). Current treatments in familial dysautonomia. Expert Opinion on Pharmacotherapy, 15(18), 2653—2671. http://dx.doi.org/10.1517/14656566.2014.970530.