Gower sign is a clinical finding that strongly suggests Duchenne muscular dystrophy (DMD) in young children, typically aged 2-5 years. It reflects pelvic girdle muscle weakness and is characterized by a child using their hands to push against their legs when rising from the floor.

Clinicians should assess this sign in children with progressive difficulty running, jumping, or climbing stairs, particularly when accompanied by frequent falls. Delayed language development, communication difficulties, and learning problems can also occur.

How Is Gower Sign Identified?

The clinician asks the child to stand up from a lying position on the floor. The child first rolls onto their stomach and then pushes up using their hands. To straighten the trunk and stand upright, the child places their hands on their knees and gradually moves them up their thighs (Figure 1).

Other clinical findings may include a waddling gait, calf muscle pseudohypertrophy, and lumbar hyperlordosis.

The clinical history should include questions about the family history of DMD.

If the disease is suspected, the child should be referred promptly to a specialized neuromuscular center to confirm the diagnosis and rule out other conditions. Multidisciplinary care should be initiated as early as possible. The referral center recommends discussing the diagnosis first with both parents without the child present, followed by a discussion with the child in the presence of their parents.

Diagnosis, Causes, and Disease Progression of DMD

Diagnosis is established on the basis of clinical findings and additional evaluations, including:

• Serum creatine kinase. Levels are typically substantially elevated, often between 5000 and 10,000 IU/L.
• Muscle biopsy. This may be used to assess muscle necrosis and identify dystrophin deficiency.
• Genetic testing. This identifies disease-causing mutations in the DMD gene on the X chromosome.

Once the diagnosis is confirmed, clinicians assess motor function, respiratory status, cardiac function, and cognitive development.

DMD is an X-linked recessive disorder that affects boys almost exclusively. According to the source, 150-200 new cases are diagnosed annually in France.

The disease is caused by mutations in the DMD gene, which encodes dystrophin, a protein that maintains the structural integrity of muscle cells.

In DMD, dystrophin is absent from skeletal muscle and may also be absent from other tissues, including the heart and brain.

In Becker muscular dystrophy, mutations in the DMD gene result in reduced amounts of dystrophin or the production of a shorter form of the protein. The clinical presentation is similar to that of DMD, in which the Gower sign can also be identified, but symptoms typically begin later, between 7 and 14 years of age, and disease progression is slower.

Dystrophin deficiency leads to muscle necrosis, followed by cycles of regeneration that eventually cease. Muscle fibers are gradually replaced by fibrous adipose tissues. Loss of the ability to walk typically occurs between 7 and 14 years of age.

Treatment and Prognosis

DMD can lead to respiratory failure, requiring mechanical ventilation, and cardiomyopathy with progressive left ventricular dysfunction. Although no cure is currently available, advances in treatment have extended life expectancy into adulthood, sometimes beyond the age of 40 years.

Corticosteroids are the only medications shown to have beneficial effects on motor function in patients with DMD. Ataluren, which was indicated for patients aged 5 years or older with specific mutations, is no longer approved in Europe or available in France. Several other treatments are currently being investigated. Among the new drugs, only givinostat has received conditional marketing authorization for the treatment of DMD, and it acts by reducing muscle inflammation and fibrosis.

This story was translated from Univadis France, part of the Medscape Professional Network.