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- $Unique_ID{BRK04019}
- $Pretitle{}
- $Title{Muscular Dystrophy, Duchenne}
- $Subject{Muscular Dystrophy, Duchenne Pseudohypertrophic Muscular Dystrophy
- Childhood Muscular Dystrophy DMD Muscular Dystrophy, Classic X-linked
- Recessive Progressive Muscular Dystrophy of Childhood Glycerol Kinase
- Deficiency Muscular Dystrophy, Batten Turner }
- $Volume{}
- $Log{}
-
- Copyright (C) 1985, 1988, 1989, 1992 National Organization for Rare
- Disorders, Inc.
-
- 37:
- Muscular Dystrophy, Duchenne
-
- ** IMPORTANT **
- It is possible that the main title of the article (Muscular Dystrophy,
- Duchenne) is not the name you expected. Please check the SYNONYMS listing to
- find the alternate name and disorder subdivisions covered by this article.
-
- Synonyms
-
- Pseudohypertrophic Muscular Dystrophy
- Childhood Muscular Dystrophy
- DMD
- Muscular Dystrophy, Classic X-linked Recessive
- Progressive Muscular Dystrophy of Childhood
-
- Information on the following diseases can be found in the Related
- Disorders section of this report:
-
- Glycerol Kinase Deficiency
- Muscular Dystrophy, Batten Turner
-
- 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.
-
-
- Duchenne Muscular Dystrophy is a rare inherited neuromuscular disorder
- and one of the most prevalent types of muscular dystrophy. This disorder is
- characterized by rapid progression of muscle degeneration which occurs early
- in life. Almost all affected children are male.
-
- Symptoms
-
- Duchenne Muscular Dystrophy is a rare inherited disorder characterized by
- progressive muscle weakness. Early symptoms usually begin between the ages
- of 2 to 5 years. Muscle wasting is initially limited to the shoulder and
- pelvic areas. Infiltration of fat and connective tissue into the muscles may
- produce an enlargement (hypertrophy) of the calf muscles in the legs. Within
- several years Duchenne Muscular Dystrophy affects the muscles of the upper
- trunk and arms. Eventually all the major muscles are affected.
-
- The early symptoms of Duchenne Muscular Dystrophy may include falling, a
- waddling walk (gait) and awkwardness. Generally these earliest signs are
- attributed to clumsiness. By the age 3 to 5 years, generalized muscle
- weakness becomes more obvious. Parents may be falsely encouraged by a
- seeming improvement between the ages of 3 and 7, but this may be due to
- natural growth and development. Weakness progresses rapidly after age 8 or
- 9, resulting in the inability to walk or stand alone. Leg braces may make
- walking possible for a year or two, but by early adolescence walking becomes
- impossible.
-
- In the late stages of Duchenne Muscular Dystrophy there is a noticeable
- shortening of muscles and the loss of muscle tissue. This may result in the
- inability to move the major joints of the body (fixed contractures). There
- may also be a noticeable increase in the curvature of the spine (scoliosis).
- Lung capacity may decrease, resulting in an increased susceptibility to
- respiratory infections.
-
- Tests are available to detect muscular dystrophy either before or after
- birth. The prenatal genetic test determines whether the fetus is carrying
- the Duchenne Muscular Dystrophy gene. The postnatal test uses antidystrophin
- antibodies to locate dystrophin in muscle tissue.
-
- Dystrophin is a protein normally found in muscles. People with Duchenne
- Muscular Dystrophy are deficient in dystrophin whereas people with Becker
- Muscular Dystrophy have a normal amount of dystrophin in the tissue, but the
- molecule is abnormally small or large. People with Becker Muscular Dystrophy
- generally have the same symptoms as those with Duchenne Muscular Dystrophy.
- However, the symptoms of Becker Muscular Dystrophy generally appear later in
- life than those of Duchenne Muscular Dystrophy, and they do not progress as
- quickly.
-
- Causes
-
- Duchenne Muscular Dystrophy is a rare neuromuscular disorder that is
- inherited as an X-linked recessive trait. The gene that is responsible for
- this disorder has been identified on the short arm of the X chromosome.
- Symptoms develop due to a lack of the protein dystrophin in the muscles.
-
- 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. X-linked recessive disorders are conditions that are coded on the X
- chromosome. Females have two X chromosomes, but males have one X chromosome
- and one Y chromosome. Therefore, in females, disease traits on the X
- chromosome can be masked by the normal gene on the other X chromosome. Since
- males only have one X chromosome, if they inherit a gene for a disease
- present on the X, it will be expressed. Men with X-linked disorders transmit
- the gene to all their daughters, who are carriers, but never to their sons.
- Women who are carriers of an X-linked disorder have a fifty percent risk of
- transmitting the carrier condition to their daughters, and a fifty percent
- risk of transmitting the disease to their sons.
-
- Approximately 30 percent of patients with Duchenne Muscular Dystrophy
- have no family history of the disorder. This can mean that the genetic
- mutation is new in those families (spontaneous). The disorder is diagnosed
- by finding a deficiency of dystrophin in the muscles.
-
- Affected Population
-
- All of the muscular dystrophies combined together affect approximately 40,000
- people in the United States. Duchenne Muscular Dystrophy is one of the most
- prevalent forms of Muscular Dystrophy. This type of Muscular Dystrophy
- affects males almost exclusively. It is estimated that approximately 1 in
- every 4,000 newborn males has Duchenne Muscular Dystrophy in the United
- States.
-
- Related Disorders
-
- Symptoms of the following disorders can be similar to those of Duchenne
- Muscular Dystrophy. Comparisons may be useful for a differential diagnosis:
-
-
- Glycerol Kinase Deficiency is a rare inborn error of metabolism that
- produces adrenal cortical insufficiency and adrenal atrophy. The major
- characteristics of this disorder are muscular weakness and developmental
- delays. The muscle atrophy seen in Glycerol Kinase Deficiency is almost
- indistinguishable from that in Duchenne Muscular Dystrophy. Many patients
- have muscle wasting and weakness with elevated creatine kinase levels that
- can be identified through laboratory tests.
-
- Batten Turner Muscular Dystrophy is a rare form of muscular dystrophy
- that is present at birth. The initial symptoms of this disorder in the
- infant may be a generalized "floppiness" and lack of muscle tone (hypotonia).
- Later muscular weakness may make the child prone to falling and stumbling.
- Early motor development and milestone achievements may be minimally delayed.
- As a rule, walking becomes normal later in life, but physical activities may
- be hampered. (For more information on this disorder, choose "Batten Turner
- Muscular Dystrophy" as your search term in the Rare Disease Database).
-
- Therapies: Standard
-
- Treatment for Duchenne Muscular Dystrophy is symptomatic and supportive.
- Physical therapy and orthopedic devices can alleviate some of the symptoms of
- this disorder.
-
- Therapies: Investigational
-
- The gene that is defective in people with Duchenne Muscular Dystrophy appears
- to serve as the blueprint for the manufacture of the protein dystrophin in
- muscle tissue. Symptoms occur when dystrophin is completely absent from the
- muscles. With this knowledge, scientists are investigating how to replace
- dystrophin in the body of people with Duchenne Muscular Dystrophy.
-
- Scientists are studying the use of the corticosteroid drug, prednisone,
- as a treatment for Duchenne Muscular Dystrophy. Preliminary results suggest
- that prednisone improves muscle strength in patients affected by this
- disorder. It is not yet clear whether prolonged treatment with
- corticosteroids will be safe and effective since these drugs can have severe
- side effects.
-
- This disease entry is based upon medical information available through
- October 1992. 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 Duchenne Muscular Dystrophy, please contact:
-
- National Organization for Rare Disorders (NORD)
- P.O. Box 8923
- New Fairfield, CT 06812-1783
- (203) 746-6518
-
- Muscular Dystrophy Association, National Office
- 3561 E. Sunrise Dr.
- Tucson, AZ 85718
- (602) 529-2000
-
- NIH/National Institute of Neurological Disorders & Stroke (NINDS)
- 9000 Rockville Pike
- Bethesda, MD 20892
- (301) 496-5751
- (800) 352-9424
-
- Muscular Dystrophy Group of Great Britain and Northern Ireland
- Nattrass House
- 35 Macaulay Road
- London, England SW4 OQP
- 01-720-8055
-
- Society for Muscular Dystrophy International
- P.O. Box 479
- Bridgewater, Nova Scotia, Canada B4V 2X6
-
- For Genetic Information and Genetic Counseling Referrals:
-
- 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
-
- MENDELIAN INHERITANCE IN MAN, 10th Ed.: Victor A. McKusick, Editor: Johns
- Hopkins University Press, 1992. Pp. 1916-1922.
-
- CECIL TEXTBOOK OF MEDICINE, 19th Ed.: James B. Wyngaarden, and Lloyd H.
- Smith, Jr., Editors; W.B. Saunders Co., 1990. Pp. 2253-2255.
-
- PRINCIPLES OF NEUROLOGY, 4th Ed.; Raymond D. Adams, M.D. and Maurice
- Victor, M.D., Editors; McGraw-Hill Information Services Company, 1989. Pp.
- 118-121.
-
- RANDOMIZED, DOUBLE-BLIND SIX-MONTH TRIAL OF PREDNISONE IN DUCHENNE'S
- MUSCULAR DYSTROPHY. J.R. Mendell, et al.; new Eng J of Med (June 15, 1989,
- issue 320(24)). Pp. 1592-1597.
-
-