Pompe is an inherited condition that affects many different parts of the body. It is considered a lysosomal storage disorder because people with Pompe 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 two major forms of Pompe which differ in regards to disease severity and age of onset. Infantile-onset Pompe is the most severe form and requires immediate treatment. Late-onset Pompe is less severe and can present at any age, but may not require treatment right away. The symptoms and long term outcome of each form vary widely. For the best possible outcome, it is important to detect Pompe early and begin proper treatment immediately.
Lysosomal Storage Disorders
Pompe is estimated to affect one in every 40,000 newborn babies in the United States. Worldwide, the incidence of this condition varies depending on ethnicity and geographic region.
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
Your baby’s doctor may ask you if your baby is showing any of the signs of Pompe (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 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 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 involves checking your baby’s blood and urine. When a child has a lysosomal storage disorder, harmful amounts of certain substances build up in the body because an enzyme that helps 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. Low levels of acid alpha-glucosidase (GAA) in the blood, high levels of sugars called glucose tetrasaccharide in the urine, and/or high levels of the enzyme, creatine kinase, in the blood may indicate that your baby has Pompe. Your baby’s doctor will also perform genetic testing to confirm the diagnosis.
The severity and age of onset of Pompe differ depending on the form.
Signs of classic infantile-onset Pompe begin before or shortlyafter birth and include:
- Muscle weakness (myopathy)
- Enlarged heart (cardiomyopathy)
- Poor muscle tone (hypotonia)
- Failure to gain weight and grow at expected rate (failure to thrive)
- Difficulty breathing
- Trouble feeding
- Respiratory infections
- Hearing problems
If your baby shows any of these signs, be sure to contact your baby's health care provider immediately.
Signs of late-onset Pompe can present at any age. The symptoms vary widely and some children with late-onset Pompe can have:
- Delayed motor skills
- Progressive muscle weakness (myopathy)
Children with late-onset Pompe will not have an enlarged heart within the first year of life. In general, the symptoms of late-onset Pompe are usually milder and progress more slowly than infantile Pompe. Most newborns with late-onset Pompe do not have obvious symptoms.
Enzyme Replacement Therapy
Your baby’s health care provider may recommend your baby start enzyme replacement therapy (ERT) to improve the signs and symptoms of Pompe. 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. Treatment with ERT is required immediately for babies with infantile-onset Pompe. Treatment for late-onset Pompe is generally not required for newborns, and is started at various ages, depending on symptom presentation and severity.
Physical therapy will be necessary to help infants, children, and adolescents develop motor skills, maintain range of motion, and strengthen muscles and joints. All children (including infantile-onset and late-onset Pompe) will likely receive physical therapy at some point.
Because lung infections and breathing difficulties are common in children with Pompe, your baby may need to be followed by a pulmonologist and have regular evaluations to check their lung function. Some patients with progressive breathing difficulty need a device to help them breathe, such as a BiPAP machine. Early treatment with ERT can reduce the chance a child with Pompe will need assistance with breathing.
Some babies with Pompe 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 they need for proper growth and development. Some children with Pompe are managed on a soft diet, while others may require a feeding tube. Early treatment with ERT can reduce the chance a child with Pompe will need assistance with feeding.
When Pompe 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 is so important.
Although children with infantile-onset Pompe may experience medical challenges throughout their lives, early treatment provides the best outcomes with a prolonged lifespan through childhood and adulthood. Individuals 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, their 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.
Pompe is an autosomal recessive genetic condition. This means that a child must inherit two copies of the non-working gene for Pompe, 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. If both parents are carriers of Pompe disease, there is a 25% (or 1 in 4) chance of having a child with Pompe with each pregnancy. It is possible to have more than one child with Pompe disease.
Learn more about autosomal recessive inheritance.
Support for Pompe
Support groups can help connect families who have a child or other family member affected with Pompe 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.
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 have developmental delays. If you think that your baby is not meeting their developmental milestones, ask your baby’s doctor about the next steps in accessing a developmental evaluation and care.
Because Pompe 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 American College of Medical Genetics and Genomics (ACMG) 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 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. 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.
References & Sources
Visit GeneReviews for more information on pompe
Visit MedlinePlus Genetics for more condition information
Kishnani P, Hwu W, Mandel H, et al. A retrospective, multinational, multicenter study on the natural history of infantile-onset Pompe disease. J Pediatr. 2006; 148(5): 671-76.e2.