What is Duchenne
Duchenne muscular dystrophy (DMD) is a lethal X-linked recessive disorder caused by the lack of the muscle protein dystrophin, which leads to progressive muscle wasting and weakness. Despite exhaustive palliative care, patients are usually restricted to a wheelchair by the age of 12 years.
The urgent need and drive towards the development of novel therapeutic approaches in pediatric neuromuscular disorders is exemplified by DMD. There is no cure, yet there is a great unmet clinical need because DMD is one of the most common genetic disorders, with an estimated 50,000 boys affected worldwide.
What causes DMD?
The genetic change that causes Duchenne, a mutation in the DMD gene, happens before birth and can be inherited, or new mutations in the gene can occur spontaneously. This mutation prevents the body from producing dystrophin, a protein that muscles need to work properly. The dystrophin protein is the largest protein in the body, is found dispersed throughout the skeletal, cardiac and smooth muscle tissue. Without this protein, the muscles become increasingly weaker, until the body can no longer survive.
Why does DMD affect mostly boys?
Since the dystrophin gene is carried on the X-chromosome, the disease is either passed on by a mother who is a genetic carrier of the mutated dystrophin gene or is caused by a spontaneous mutation in the dystrophin gene after conception. This means that a mother carrying a healthy gene can give birth to a child with DMD. Because the dystrophin gene is carried on the X-chromosome, this disease usually affects boys, since girls have two X-chromosomes and can fall back on one if the other carries a faulty gene.
What happens to children with DMD?
Children are usually diagnosed when they begin to walk because muscle weakness gives them trouble. By the early to mid-teen years, they are usually non-ambulatory, completely wheelchair dependent and by their early-twenties may be ventilator dependent. Due to advances in cardiac and respiratory care, life expectancy is increasing.
Signs and Symptoms of DMD
Progressive muscle weakness is the main symptom of muscular dystrophy. Symptoms usually appear before age 6 and may appear as early as infancy. Other early signs and symptoms may be:
Clumsiness, falling often
Large calf muscles
Difficulty staying awake
Treatments for Duchenne Muscular Dystrophy
There is no current cure for DMD. Treatment is aimed at controlling the symptoms and maximizing the quality of life. Current treatments are:
Corticosteroids to increase energy and strength and delay the progression of the disease
Orthopedic braces and corrective surgery