Also known as:
- Acid maltase deficiency disease
- Alpha-1,4-glucosidase deficiency
- Deficiency of alpha-glucosidase
- GAA deficiency
- Glycogenosis Type II
- Glycogen storage disease type II
- GSD II
Pompe disease is an inherited condition that affects many different parts of the body. It is considered a lysosomal storage disorder because people with Pompe disease have lysosomes (the recycling center of each cell) that cannot break down certain types of complex sugars. This causes undigested sugar molecules and other harmful substances to build up in cells throughout the body, resulting in a variety of symptoms.
There are three forms of Pompe disease which differ in regards to disease severity and age of onset. The symptoms and long term outcome of each form vary widely. For the best possible outcome, it is important to detect Pompe disease early and begin proper treatment immediately.
Your baby’s doctor may ask you if your baby is showing any of the signs of Pompe disease (see Early Signs below). If your baby has certain signs, your baby’s doctor may suggest starting immediate treatment.
If your baby’s newborn screening result for Pompe disease was out of the normal range, your baby’s doctor or the state screening program will contact you to arrange for your infant to have additional testing. It is important to remember that an out-of-range screening result does not necessarily mean that your child has the condition. An out-of-range result may occur because the initial blood sample was too small or the test was performed too early. However, as a few babies do have the condition, it is very important that you go to your follow-up appointment for a confirmatory test. Because the harmful effects of untreated Pompe disease can occur soon after birth, follow-up testing must be completed as soon as possible to determine whether or not your baby has the condition.
Follow-up testing will involve checking your baby’s blood, urine, and a small sample of skin or muscle tissue for signs of Pompe disease. When a child has a lysosomal storage disorder, harmful amounts of certain substances build up in the body and an enzyme that help the body breakdown sugars is either missing or has reduced activity. Evaluating these substances in your baby’s body can help doctors determine if your baby has a condition. High levels of sugars called tetrasaccharide in the urine, high levels of the enzyme, creatine kinase, in the blood or deficient activity of the enzyme, acid alpha-glucosidase (GAA), in the blood or skin/muscle cells may indicate that your baby has Pompe disease. Your baby’s doctor may wish to confirm the diagnosis with clinical genetic testing.
About Pompe disease
The severity and age of onset of Pompe disease differ depending on the form.
Signs of classic infantile-onset Pompe disease begin before or shortlyafter birth and include:
- Muscle weakness (myopathy)
- Poor muscle tone (hypotonia)
- Failure to gain weight and grow at expected rate (failure to thrive)
- Difficulty breathing
- Trouble feeding
- Respiratory infections
- Hearing problems
Signs of non-classic infantile-onset Pompe disease usually occur by age one and include:
- Delayed motor skills
- Progressive muscle weakness (myopathy)
- Difficulty breathing
Late-onset Pompe disease may develop in childhood, adolescence, or even adulthood. It is also associated with progressive muscular weakness and difficulty breathing. However, the symptoms are usually milder and progress more slowly than the other forms of Pompe disease.
If your baby shows any of these signs, be sure to contact your baby’s health care provider immediately.
Enzyme Replacement Therapy
Your baby’s health care provider may recommend your baby go on enzyme replacement therapy (ERT) to improve the signs and symptoms of Pompe disease. This treatment aims to supplement the enzymes that are present at low levels in your baby’s lysosomes. ERT can stabilize your baby’s organ function, improving motor skills, and reducing heart enlargement.
Physical therapy will be necessary to help infants, children, and adolescents develop motor skills, maintain range of motion, and strengthen muscles and joints.
Because lung infections and breathing difficulties are common in children with Pompe disease, your baby may need to use a CPAP or BiPAP machine. A CPAP machine helps to keep your child’s airways open and a BiPAP machine helps your child inhale more air into his or her lungs.
Many babies with Pompe disease have trouble feeding and gaining weight. A nutritionist or dietician can help you monitor your baby’s calorie intake and plan a diet that will provide the nutrients he or she needs for proper growth and development. Some children with Pompe disease are managed on a soft diet, while others may require a feeding tube.
When Pompe disease is detected early and proper treatment is started immediately, many babies with the condition are able to live longer lives with improved growth, development and organ function. This is why newborn screening for Pompe disease is so important.
Even with treatment, children with both forms of infantile-onset Pompe disease usually pass away in early childhood. Individual with late-onset Pompe disease often have longer lifespans with slower disease progression.
Structures called lysosomes are the recycling centers within our cells. Lysosomes contain enzymes that help the cell breakdown and reuse certain materials from the foods we eat. Some enzymes help the lysosome breakdown complex sugars, specifically. One of these enzymes is called acid alpha-glucosidase (GAA).
If your baby has Pompe disease, his or her body is missing or making non-working copies of GAA enzymes. When this enzyme is not working correctly, your baby’s body cannot break down a large sugar molecule called glycogen into smaller components. This causes undigested sugar molecules and other harmful substances to build up in cells throughout the body, resulting in the many signs and symptoms of Pompe disease.
Pompe disease is an autosomal recessive genetic condition. This means that a child must inherit two copies of the non-working gene for Pompe disease, one from each parent, in order to have the condition. The parents of a child with an autosomal recessive condition each carry one copy of the non-working gene, but they typically do not show signs and symptoms of the condition.
While having a child with Pompe disease is rare, when both parents are carriers, they can have more than one child with the condition. Learn more about autosomal recessive inheritance.
Support for Pompe disease
Support groups can help connect families who have a child or other family member affected with Pompe disease with a supportive community of people who have experience and expertise in living with the condition. These organizations offer resources for families, affected individuals, health care providers, and advocates.
Acid Maltase Deficiency Organization
Association for Glycogen Storage Disease
International Pompe Association
Work with your baby’s health care provider to determine the next steps for your baby’s care. Your baby’s doctor may help you coordinate care with a dietician or nutritionist, physical therapists, physicians that specialize in metabolism, cardiology, and pulmonology, and other medical resources in your community. Some children with Pompe disease have developmental delays. If you think that your baby is not meeting his or her developmental milestones, ask your baby’s doctor about the next steps in accessing a developmental evaluation and care.
Because Pompe disease is a genetic condition, you may want to talk with a genetics specialist. A genetic counselor or geneticist can help you understand the causes of the condition, discuss genetic testing for Pompe disease, and understand what this diagnosis means for other family members and future pregnancies. Speak with your baby’s doctor about getting a referral. The Clinic Services Search Engine offered by the National Coordinating Center for the Regional Genetic and Newborn Screening Service Collaboratives and the Find a Genetic Counselor tool on the National Society of Genetic Counselors (NSGC) website are two good resources for you or your baby's health care provider to use to identify local specialists.
Phoenix is a young boy who was diagnosed with infantile-onset Pompe disease at six months of age. Read the story of his diagnosis and how Enzyme Replacement Therapy saved his life.
Azaria is a sweet, bright child who was diagnosed with Pompe disease. Despite having a childhood in and out of the hospital for Enzyme Replacement Therapy and speech and eating therapy, Azaria is energetic and happy. Read her inspirational story.