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- $Unique_ID{BRK04044}
- $Pretitle{}
- $Title{Neuropathy, Congenital Hypomyelination}
- $Subject{Neuropathy Congenital Hypomyelination CHN Congenital Dysmyelinating
- Neuropathy Congenital Hypomyelinating Polyneuropathy CHN Congenital
- Hypomyelination Congenital Hypomyelination Neuropathy Congenital
- Hypomyelination Onion Bulb Polyneuropathy Congenital Neuropathy
- Hypomyelination Congenital Neuropathy Early Infantile Neuropathy Infantile
- Neuropathy Hypomyelination Neuropathy Dejerine-Sottas Disease Guillain-Barre
- Syndrome }
- $Volume{}
- $Log{}
-
- Copyright (C) 1990 National Organization for Rare Disorders, Inc.
-
- 822:
- Neuropathy, Congenital Hypomyelination
-
- ** IMPORTANT **
- It is possible that the main title of the article (Congenital
- Hypomyelination Neuropathy) is not the name you expected. Please check the
- SYNONYM listing to find the alternate names and disorder subdivisions covered
- by this article.
-
- Synonyms
-
- CHN
- Congenital Dysmyelinating Neuropathy
- Congenital Hypomyelinating Polyneuropathy (CHN)
- Congenital Hypomyelination
- Congenital Hypomyelination Neuropathy
- Congenital Hypomyelination (Onion Bulb) Polyneuropathy
- Congenital Neuropathy caused by Hypomyelination
- Congenital Neuropathy
- Early Infantile Neuropathy
- Infantile Neuropathy
- Hypomyelination Neuropathy
-
- Information on the following disorders can be found in the Related
- Disorders section of this report:
-
- Dejerine-Sottas Disease
- Guillain-Barre Syndrome
-
- 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.
-
- Congenital Hypomyelination Neuropathy is a neurological disorder present
- at birth. Major symptoms can include respiratory difficulty, muscle weakness
- and incoordination, poor muscle tone, absence of reflexes, difficulty in
- walking, and/or impaired abilities to feel or move part of the body.
-
- Symptoms
-
- Symptoms of Congenital Hypomyelination Neuropathy and the severity of these
- symptoms vary from patient to patient. Major symptoms can include delayed
- motor (muscle) development (ability to turn over, stand, crawl, walk, etc.),
- muscle weakness, poor muscle tone (hypotonia), impaired muscle coordination,
- absence of reflexes (areflexia), difficulty in walking or crawling, and/or
- impaired ability to feel or move part of the body (mild distal palsy). In
- some infants, respiratory problems or difficulty in swallowing may occur.
- Abnormal microscopic changes in certain nerves such as sural nerves (located
- in the calf of the leg) can occur.
-
- Causes
-
- The exact cause of Congenital Hypomyelination Neuropathy is unknown. The
- cause of many disorders involving the myelin sheath (the protective sheath
- surrounding the nerves), such as Multiple Sclerosis, is unknown. A recurrent
- loss and repair of myelin causes Congenital Hypomyelination Neuropathy.
- Scientists do not yet know why the myelin disappears, nor do they know why it
- grows back.
-
- Some researchers believe, although this has not yet been established,
- that Congenital Hypomyelination Neuropathy may be a subtype of Dejerine-
- Sottas Disease which is inherited as an autosomal dominant 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 autosomal dominant disorders, a single abnormal gene, contributed
- by either parent, overrides the normal gene contributed by the other parent
- causing disease. Individuals with one affected parent have a 50% chance of
- inheriting the disorder. (For more information on Dejerine-Sottas Disease,
- see the Related Disorders section of this report).
-
- Other disorders characterized by the loss and repair of the myelin sheath
- may be autoimmune disorders. In autoimmune disorders the body's defenses
- against disease (e.g. antibodies or lymphocytes) attack healthy tissue for
- unknown reasons.
-
- Affected Population
-
- Congenital Hypomyelination Neuropathy is a rare disorder present at birth.
- It affects males and females in equal numbers.
-
- Related Disorders
-
- Dejerine-Sottas Disease is a hereditary neurological disorder which
- progressively affects muscle function. Peripheral nerves become enlarged and
- thickened causing an irregular progression of muscle weakness. Pain,
- weakness, numbness, and a tingling, prickling or burning sensation can occur
- in the patient's legs. Other symptoms include loss of heat sensitivity,
- absence of reflexes and atrophy of leg muscles. The hand and forearm muscles
- may become weak in later stages. Mild vision difficulties may also occur.
- (For more information on this disorder, choose "Dejerine-Sottas" as your
- search term in the Rare Disease Database).
-
- Guillain-Barre Syndrome (Acute Idiopathic Polyneuritis) occurs when the
- body's immune system (antibodies, lymphocytes) attacks the nerves, damaging
- the nerve's myelin and axon. Nerve signals are delayed and altered, causing
- weakness and paralysis of the muscles of the legs, arms, and other parts of
- the body along with abnormal sensations. When muscle nerves are damaged, the
- patient experiences aching and weak muscles, difficulty getting up from
- chairs or walking stairs, difficulty lifting objects, shortness of breath,
- and/or difficulty in swallowing. With proper treatment, most patients with
- Guillain-Barre Syndrome can expect to lead full and active lives. (For more
- information on this disorder, choose "Guillain" as your search term in the
- Rare Disease Database).
-
- Therapies: Standard
-
- Testing for Congenital Hypomyelination Neuropathy may include recording of
- electrical impulses produced by the muscles (electromyogram), as well as
- nerve and/or muscle biopsies. Treatment of Congenital Hypomyelination
- Neuropathy is symptomatic and supportive.
-
- Therapies: Investigational
-
- This disease entry is based upon medical information available through
- December 1990. 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 Congenital Hypomyelination Neuropathy, please
- contact:
-
- National Organization for Rare Disorders
- P.O. Box 8923
- New Fairfield, CT 06812-1783
- (203) 746-6518
-
- NIH/National Institute of Neurological Disorders & Stroke (NINDS)
- 9000 Rockville Pike
- Bethesda, MD 20892
- (301) 496-5751
- (800) 352-9424
-
- For genetic information and genetic counseling referrals, please contact:
-
- March of Dimes Birth Defects Foundation
- 1275 Mamaroneck Avenue
- White Plains, NY 10605
- (914) 428-7100
-
- Alliance of Genetic Support Groups
- 35 Wisconsin Circle, Suite 440
- Chevy Chase, MD 20815
- (800) 336-GENE
- (301) 652-5553
-
- References
-
- THE MERCK MANUAL, Volume 1, 15th Ed.: Robert Berkow, M.D., ed.-in-chief;
- Merck, Sharp, and Dohme Laboratories, 1987. Pp. 1433-1434.
-
- A CASE OF CONGENITAL HYPOMYELINATION NEUROPATHY. CLINICAL,
- MORPHOLOGICAL, AND CHEMICAL STUDIES. W.R. Kennedy, et al.; Arch Neurol (Jun
- 1977; issue 34 (6)). Pp. 337-345.
-
- CONGENITAL HYPOMYELINATION NEUROPATHY IN A NEWBORN. S. Hakamada, et al.;
- Neuropediatrics (Aug 1983; issue 14 (3)). Pp. 182-183.
-
- CONGENITAL HYPOMYELINATION POLYNEUROPATHY. PATHOLOGICAL FINDINGS
- COMPARED WITH POLYNEUROPATHIES STARTING LATER IN LIFE. F. Guzzetta, et al.;
- Brain (Jun 1982; issue 105 (Pt 2)). Pp. 395-416.
-
- TWO CASES OF CONGENITAL HYPOMYELINATION NEUROPATHY. N. Tachi, et al.;
- Brain Dev (1984; issue 6 (6)). Pp. 560-565.
-
-