X-linked recessive inheritance
Find information on thousands of medical conditions and prescription drugs.

Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) (also known as pseudohypertrophic muscular dystrophy or muscular dystrophy - Duchenne type) is an inherited disorder characterized by rapidly progressive muscle weakness which starts in the legs and pelvis and later affects the whole body. Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy. It usually affects only boys, but in rare cases it can also affect girls. It is an X-linked recessive inherited disease. A milder form of this disease is known as Becker Muscular dystrophy (BMD). In Becker muscular dystrophy, most of the symptoms are similar to Duchenne, but the onset is later and the course is milder. more...

Dandy-Walker syndrome
Darier's disease
Demyelinating disease
Dengue fever
Dental fluorosis
Dentinogenesis imperfecta
Depersonalization disorder
Dermatitis herpetiformis
Dermatographic urticaria
Desmoplastic small round...
Diabetes insipidus
Diabetes mellitus
Diabetes, insulin dependent
Diabetic angiopathy
Diabetic nephropathy
Diabetic neuropathy
Diamond Blackfan disease
Diastrophic dysplasia
Dibasic aminoaciduria 2
DiGeorge syndrome
Dilated cardiomyopathy
Dissociative amnesia
Dissociative fugue
Dissociative identity...
Dk phocomelia syndrome
Double outlet right...
Downs Syndrome
Duane syndrome
Dubin-Johnson syndrome
Dubowitz syndrome
Duchenne muscular dystrophy
Dupuytren's contracture
Dyskeratosis congenita
Dysplastic nevus syndrome

DMD is named after the French neurologist Guillaume Benjamin Amand Duchenne (1806-1875), who first described the disease in the 1860s. One third of the cases are known to be caused by development of spontaneous mutations in the dystrophin gene, while the remainder are inherited. Boys with DMD develop weak muscles because the muscle fibers that were present at birth are destroyed. It is due to mutations in the dystrophin gene, which encodes a cell membrane protein in myocytes (muscle cells).


Symptoms usually appear in males between 1 and 6 years of age, however females, on rare occasions, can develop the disease. By age 10, braces may be required for walking, and by age 12, most children require use of a wheelchair for mobility. Bones may develop abnormally, causing skeletal deformities of the spine and other areas due to contractures (shortening of muscle tissue). Muscular weakness and skeletal deformities contribute to frequent breathing disorders. Cardiomyopathy occurs in almost all cases. Intellectual impairment occurs in approximately 30% of Duchenne's patients, but does not worsen as the disorder progresses. Duchenne muscular dystrophy occurs in approximately 1 out of 3,500 males. Because this is an inherited disorder, risks include a family history of Duchenne muscular dystrophy. A mother carrying the Duchenne gene has a 50% chance of passing the disease on to any male children.

In contrast, Becker muscular dystrophy is a form that starts later and progresses much more slowly. The key complication in BMD is cardiomyopathy, and patients must take care to monitor their cardiac health.


Duchenne dystrophy is a type of dystrophinopathy which includes a spectrum of muscle disease caused by mutations in the DMD gene, which encodes the protein dystrophin. Becker's muscular dystrophy is a milder type of dystrophinopathy. Although it is caused by a defective gene, it often occurs in people from families without a known family history of the condition.

Duchenne muscular dystrophy is inherited in an X-linked recessive pattern. This means that women are almost never affected; women normally have two X chromosomes, one of which contains a normal, dominant copy of the gene that will make enough of the protein for them to avoid symptoms. Women who carry the defective gene can pass an abnormal X on to their sons, however. Since boys have an X from their mother and a Y from father, there is no second X to make up for the defective gene from the carrier mother. The sons of carrier females each have a 50% chance of having the disease, and the daughters each have a 50% chance of being carriers. Daughters of men with Duchenne also have a 50% chance of being carriers.

Read more at Wikipedia.org

[List your site here Free!]

Steroid slackens pace of muscular dystrophy - prednisone and Duchenne's muscular dystrophy
From Science News, 4/27/91 by Kathy A. Fackelmann

Steriod slackens pace of muscular dystrophy

A powerful steroid has poved its mettle as the first drug to slow progressive muscle weakening in youngsters with Duchenne's muscular dystrophy. Although the drug, called prednisone, carries serious side effects, researchers believe it may ultimately point the way to an equally effective but safer treatment.

"For the first time, we have a long-term study that shows [prednisone's] efficacy," says Gerald M. Fenichel of Vanderbilt University in Nashville, who presented the results this week at the American Academy of Neurology meeting in Boston. He cautions, however, that the drug cannot rid patients of the disease. "Prednisone is not a cure," he says.

One out of every 3,500 male infants in the United States has inherited a defective gene that causes Duchenne's muscular dystrophy. At about age 3, afflicted children develop a swaying or waddling motion when they walk. From that seemingly innocent early stage, the disease advances until weakened muscles can no longer hold the body upright. Even with physical theraphy, most victims need a wheelchair by age 12, and most die of heart or lung complications by age 20.

Several years ago, a study directed by Daniel B. Drachman of Johns Hopkins University in Baltimore hinted at prednisone's potential in boys with Duchenne's -- the most serious form of muscular dystrophy (SN: 8/22/87, p.120). Fenichel and his colleagues have now confirmed that early promise in a multicenter trial of 89 Duchenne's patients ranging from 7 to 14 years of age.

In a year-long experiment, Fenichel's team found that a daily doe of 0.75 milligrams of prednisone per kilogram of body weight seemed to offer the best short at fighting the muscle-sapping disorder. After that initial phase, they continued to treat the boys but had to lower the maximum dose for some patients because of harsh side effects.

Three years later, the 49 boys taking the highest daily doses (at least 0.65 mg/kg) showed the most favorable response, Fenichel reports. Their muscle strength (measured by weight-lifting tests) declined by an average of 0.017 unit per year, whereas the boys on lower doses lost about 0.164 unit per year. Altough the study did not include a control group, Fenichel says participants showed a clear benefit compared with Duchenne's patients in general, who typically lose about 0.4 unit per year. Some volunteers actually gained muscle strength, he adds -- an improvement readily noted by their parents.

"This study reports an apparent slowing of the progression of the disease over a period of time," comments Lawrence Z. Stern of the Muscular Dystrophy Association in Tucson, Ariz. Nonetheless, he calls the results "modest." Even for children who improve, he says, the drug may delay the need for a wheelchair by only weeks or months. Drachman, on the other hand, asserts that careful prednisone treatment can postpone wheelchair confinement by two years or more.

The Muscular Dystrophy Association, citing safety concerns, does not recommend prednisone treatment. However, says Stern, if researchers could unlock the secret of the steroid's dystrophy-fighting effect, they might someday design less toxic drug treatments.

To test a hypothesis that prednisone works by suppressing a muscle-ravaging immune response, the same researchers conducted a separate study of 99 Duchenne's patients. An immunosuppressant drug called azathioprine failed to slow muscle wasting, but prednisone again showed its protective effect. Robert C. Griggs of the University of Rochester in New York, who reported the results at the Boston meeting, says this means the researchers must look beyond the immunity hypothesis.

COPYRIGHT 1991 Science Service, Inc.
COPYRIGHT 2004 Gale Group

Return to Duchenne muscular dystrophy
Home Contact Resources Exchange Links ebay