Spotlight on Pompe disease

Since Rare Disease Day, 29 February, we’ve been sharing spotlights on individual members of our community who are living with a variety of neuromuscular conditions. We want to draw attention to the fact that rare disease isn’t just for one day. And by sharing individual stories and information on conditions, we want to raise awareness about the many neuromuscular conditions experienced by the diverse members of our community to whom MDI offers support.

As International Pompe Day takes place every year in April, we want to raise awareness about this rare condition. We are unaware of anyone who is living with the condition in Ireland and so we are simply sharing information about the condition. The information will be added to a dedicated page on our website.

Pompe disease

Overview

Pompe disease is classified as a metabolic muscle disorder, one of a group of conditions that interferes with processing and storage of complex sugars (carbohydrates). Mutations in a gene that carries the genetic instructions to make an enzyme called acid maltase, or acid alpha-glucosidase (GAA), are the underlying cause of the condition. Normally, the body uses the GAA enzyme to break down glycogen (stored sugar used for energy). When the gene is mutated it is unable to make the GAA enzyme or it makes a smaller amount. This leads to a build-up of sugar molecules in muscle cells, causing them to break down, which leads to muscle weakness. The cells of the heart and skeletal muscles are the most seriously affected.

Onset of symptoms may occur at any time from infancy to adulthood. Pompe disease, is classified into two forms. The early-onset infantile form is the more severe form. It starts before 12 months of age and involves the heart muscle. The later-onset juvenile or adult form may start at any age after 12 months of age, and the heart is less likely to be severely affected.

The condition is inherited in an autosomal recessive manner, which means both parents must pass on copies of the mutated gene. Each parent is a carrier of Pompe disease, but they usually don’t show symptoms of the condition.

Signs and symptoms

Pompe disease affects many parts of the body and resulting in weakness of the skeletal, heart, and pulmonary (lung) muscles.

Infantile Pompe disease symptoms may include:

·       Trouble gaining weight and growing at the expected rate (failure to thrive).

·       Difficulty breathing.

·       Poor muscle tone.

·       Enlargement of the heart, liver and tongue.

·       Feeding issues.

·       Respiratory infections.

·       Hearing problems.

Late-onset Pompe disease symptoms may include:

·       Legs and trunk get steadily weaker.

·       Increasing difficulty walking.

·       Muscle pain over a large area.

·       Loss of the ability to exercise.

·       Falling often.

·       Frequent respiratory infections.

·       Shortness of breath when you push yourself.

·       Headaches in the morning.

·       Tiredness during the day.

·       Unintended weight loss.

·       Difficulty swallowing.

·       Irregular heartbeat.

·       Increased difficulty hearing.

Treatment

There is no cure for Pompe disease, but medication and therapy can help manage some symptoms and potentially slow the course of the condition.

Treatment should involve a multidisciplinary team of specialists (such as a cardiologist, neurologist and respiratory therapist).  Speech and language therapists, dieticians, physiotherapists, and occupational therapists are also valuable members of the multidisciplinary team and can provide recommendations and aids to improve function and quality of life. Depending on the severity of the condition, some people may need a feeding tube or mechanical ventilation to manage symptoms.

Enzyme replacement therapy (ERT) is the approved treatment for patients with Pompe disease. In ERT, a synthetic form of the maltase enzyme is delivered to cells to substitute for the enzyme missing in Pompe disease. This can help improve muscle tone and reduce glycogen storage in individuals with the condition. The ERT drug Myozyme was one of the first options available to treat infantile-onset and late-onset Pompe disease, respectively. Lumizyme and Nexviazyme are other forms of ERT now available in different countries.

Muscular Dystrophy Ireland supports people living with Pompe disease, also known as, acid maltase deficiency (AMD) or glycogen storage disease II (GSD2), and many other neuromuscular conditions. If you have any questions, you can contact us on our Information Line on +353 01 6236414 or on http://www.mdi.ie/contact.

The International Pompe Association has developed guidance for people living with the condition, Pompe Connections, which you can read here. It contains reviewed and approved information from experts around the world. Topics include:

·       Adapting to living with Pompe disease

·       Breathing problems

·       Nutrition and dietary therapy

·       Exercise and physical therapy

·       Having children when you have Pompe disease.

Disclaimer: Please note that while MDI shares information about neuromuscular conditions, we do not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.