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$Unique_ID{BRK03678}
$Pretitle{}
$Title{Dysautonomia, Familial}
$Subject{Dysautonomia, Familial FD Riley-Day Syndrome Hereditary Sensory
Neuropathy Type III HSN-III Hereditary Sensory and Autonomic Neuropathy Type
III HSAN-III Congenital Sensory Neuropathy with Anhidrosis Biemond Congenital
and Familial Analgesia Hereditary Sensory Neuropathy (HSAN II)}
$Volume{}
$Log{}

Copyright (C) 1985, 1986, 1988, 1990, 1991, 1993 National Organization
for Rare Disorders, Inc.

47:
Dysautonomia, Familial

** IMPORTANT **
It is possible that the main title of the article (Familial Dysautonomia)
is not the name you expected.  Please check the SYNONYMS listing to find the
alternate name and disorder subdivisions covered by this article.

Synonyms

FD
     Riley-Day Syndrome
     Hereditary Sensory Neuropathy Type III
     HSN-III
     Hereditary Sensory and Autonomic Neuropathy Type III
     HSAN-III

Information on the following disorders can be found in the Related
Disorders section of this report:

     Congenital Sensory Neuropathy with Anhidrosis
     Biemond Congenital and Familial Analgesia
     Hereditary Sensory Neuropathy (HSAN II)

General Discussion

** REMINDER **
The Information contained in the Rare Disease Database is provided for
educational purposes only.  It should not be used for diagnostic or treatment
purposes.  If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.


Familial Dysautonomia is a rare genetic disorder of the autonomic nervous
system (ANS) characterized by diminished sensitivity to pain, lack of
overflow tearing in the eyes, a decrease in the number of knob-like
projections that cover the tongue (fungiform papillae), unusual fluctuations
of body temperature, and unstable blood pressure.  Symptoms of this disorder
are apparent at birth.  The autonomic nervous system controls vital
involuntary body functions.

Symptoms

An infant born with Familial Dysautonomia typically has poor sucking ability,
impaired swallowing reflexes, low fluid pressure within the eye, and may have
poor muscle tone, and/or abnormally low body temperature (hypothermia).
Infants with this disorder may have cold hands and feet, and may experience
unstable body temperature (from 94 to 108 degrees) during the course of
infectious diseases.  Profuse sweating and drooling may also occur.

A decreased perception of pain and lack of sensitivity to hot and/or cold
temperatures can result in unnoticed injuries to the skin.  Sometimes a lack
of tears and insensitivity of the eyes to pain from foreign objects (corneal
anesthesia) can lead to inflammation of the corneas and ulcerations in the
eyes.

Unstable blood pressure is usually present in infants with Familial
Dysautonomia.  Blood pressure readings may vary greatly and may be abnormally
high or low.  Other symptoms of Familial Dysautonomia may include the absence
of the sense of taste, impaired speech, and/or red blotches on the skin that
appear with emotional excitement.  Approximately 40 percent of children with
this disorder experience episodes of vomiting.  Occasionally there may be
skeletal defects, absence of tendon reflexes, stunted height, and/or repeated
episodes of pneumonia due to the inhalation of food (aspiration).

By adolescence, 95 percent of patients with Familial Dysautonomia have
evidence of spinal curvature (scoliosis), and may experience increased
sweating and an accelerated heart rate.  A decreased awareness of pain makes
it difficult for a child with this disorder to report injuries, and bone
fractures may go unrecognized.  Other symptoms that may appear during
adolescence include:  weakness, leg cramping, difficulty concentrating,
and/or personality changes characterized by depression, irritability,
inability to sleep (insomnia), and/or negativism.

Approximately 20 percent of people with Familial Dysautonomia over 20
years of age develop kidney insufficiency.  Neurological deterioration also
appears, and unsteadiness in walking may become more apparent at this age.

A medical test is available that can determine if an infant has Familial
Dysautonomia.  Histamine is injected under the skin and response is measured
along nerve cell fibers (axon flare).  The lack of response yields a
diagnosis of Familial Dysautonomia.

Causes

Familial Dysautonomia is inherited as a recessive genetic trait.  Human
traits, including the classic genetic diseases, are the product of the
interaction of two genes, one received from the father and one from the
mother.  In recessive disorders, the condition does not appear unless a person
inherits the same defective gene for the same trait from each parent.  If one
receives one normal gene and one gene for the disease, the person will be a
carrier for the disease, but usually will not show symptoms.  The risk of
transmitting the disease to the children of a couple, both of whom are
carriers for a recessive disorder, is twenty-five percent.  Fifty percent of
their children will be carriers, but healthy as described above.  Twenty-five
percent of their children will receive both normal genes, one from each
parent, and will be genetically normal.

Affected Population

Familial Dysautonomia is a rare genetic disorder that affects males and
females in equal numbers.  This disorder primarily affects infants of
Ashkenazi Jewish or Eastern European ancestry; approximately 1 in 30 people
of East European Jewish ancestry are thought to be carriers of the defective
gene that causes this disorder.

Related Disorders

Symptoms of the following disorders can be similar to those of Familial
Dysautonomia.  Comparisons may be useful for a differential diagnosis:

Biemond Congenital and Familial Analgesia is a genetic disorder
characterized by symptoms that are similar to those of Familial Dysautonomia.
The symptoms of this disorder include insensitivity to pain, a diminished
sense of temperature and touch, and the absence of tendon reflexes.

Congenital Sensory Neuropathy with Anhidrosis (Hereditary Sensory and
Autonomic Neuropathy or HSAN-IV) is a rare inherited disorder of the
autonomic nervous system that is characterized by the loss of pain and
temperature sensation and a lack of sweating.  There may be wide variations
in body temperature and recurrent episodes of unexplained high fevers.  The
symptoms of Congenital Sensory Neuropathy with Anhidrosis may initially be
confused with Familial Dysautonomia.

Hereditary Sensory Neuropathy (HSAN II) is a rare inherited disorder
characterized by insensitivity to pain, a diminished sense of temperature and
touch, and the absence of tendon reflexes.  Children with this disorder
typically have decreased but not absent tear flow.  The lack of sweating and
the absence of abnormally low blood pressure upon standing (orthostatic
hypotension) helps to distinguish this disorder from Familial Dysautonomia.
(For more information on this disorder, choose "Hereditary Sensory
Neuropathy" as your search term in the Rare Disease Database.)

"Dysautonomia," when used as a general medical term, refers to the
abnormal functioning of the autonomic nervous system and can be combined with
other words to describe specific conditions such as "diabetic cardiac
dysautonomia" or "postganglionic cholinergic dysautonomia."  There are many
conditions characterized by the symptoms of dysautonomia.  These should not
be confused with the specific hereditary disorder of Familial Dysautonomia.

Therapies:  Standard

Drugs used to relieve the symptoms of Familial Dysautonomia include diazepam,
metoclopramide, and chloral hydrate.  Artificial tears may be needed to
lubricate the eyes.

Physical therapy, chest physiotherapy, occupational therapy, feeding
facilitation, and/or speech therapy may also be useful to alleviate the
symptoms of Familial Dysautonomia.

People with Familial Dysautonomia may also benefit from a variety of
other orthopedic and ocular (vision) aids.

Genetic counseling will be of benefit for patients with Familial
Dysautonomia and their families.

Therapies:  Investigational

Clinical trials are underway to study the classification of the different
types of Familial Dysautonomia (taxonomy) and therapy of orthostatic
hypotension (low blood pressure).  Interested people may wish to have their
physician contact:

     Dr. Italo Biaggioni
     AA 3228 MCN
     Vanderbilt University GCRC
     Nashville, TN  37232
     [phone]

Research on birth defects and their causes is ongoing.  The National
Institutes of Health (NIH) is sponsoring the Human Genome Project that is
aimed at mapping every gene in the human body and learning why they sometimes
malfunction.  It is hoped that this new knowledge will lead to prevention and
treatment of genetic disorders in the future.

This disease entry is based upon medical information available through
February 1993.  Since NORD's resources are limited, it is not possible to
keep every entry in the Rare Disease Database completely current and
accurate.  Please check with the agencies listed in the Resources section for
the most current information about this disorder.

Resources

For more information on Familial Dysautonomia, please contact:

     National Organization for Rare Disorders (NORD)
     P.O. Box 8923
     New Fairfield, CT 06812-1783
     [phone]

     Dysautonomia Foundation, Inc.
     20 E. 46th St., Room 302
     New York, NY 10017
     [phone]

     National Foundation for Jewish Genetic Diseases
     250 Park Ave.
     New York, NY 10177
     [phone]

     NIH/National Institute of Neurological Disorders & Stroke (NINDS)
     9000 Rockville Pike
     Bethesda, MD  20892
     [phone]
     [phone]

For Genetic Information and Genetic Counseling Referrals:

     March of Dimes Birth Defects Foundation
     1275 Mamaroneck Avenue
     White Plains, NY 10605
     [phone]

     Alliance of Genetic Support Groups
     35 Wisconsin Circle, Suite 440
     Chevy Chase, MD  20815
     (800) 336-GENE
     [phone]

References

MENDELIAN INHERITANCE IN MAN, 10th Ed.:  Victor A. McKusick, Editor:  Johns
Hopkins University Press, 1992.  Pp. 768-769, 1345-1346.

CECIL TEXTBOOK OF MEDICINE, 19th Ed.:  James B. Wyngaarden, and Lloyd H.
Smith, Jr., Editors; W.B. Saunders Co., 1990.  Pp. 2246.

PRINCIPLES OF NEUROLOGY, 4th Ed.; Raymond D. Adams, M.D. and Maurice
Victor, M.D., Editors; McGraw-Hill Information Services Company, 1989.  Pp.
453, 1033, 1056.

PRINCIPLES AND PRACTICES OF MEDICAL GENETICS, 2nd Ed.:  Allan E.H. Emery &
David L. Rimoin, Editors; Churchill Livingston Publishers, 1990.  Pp. 397-
441.

NEONATAL RECOGNITION OF FAMILIAL DYSAUTONOMIA:  F.B. Axelrod et al.; J
Pediatr (Jun 1987;110(6)).  Pp. 946-8.