Reproductive options for Pompe disease carriers
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Each year, 100 babies in the U.S., on average, are born with Pompe disease. Their parents are either carriers of the genetic mutation that causes the disorder or have the rare disease themselves.
Many women who have Pompe disease have safely delivered healthy babies. However, being pregnant while living with Pompe can put the mother in a high-risk pregnancy category.
There are some reproductive options people with Pompe may want to consider before getting pregnant, including personal genetic screening, along with in vitro fertilization and genetic analysis.
Individuals with Pompe or who are disease carriers may be able to have a fertilized egg implanted that has been tested for genetic mutations.
What is Pompe disease?
Pompe disease — also known as glycogen storage disease type 2 — is a genetic disorder caused by the toxic buildup of a sugar molecule called glycogen in cells, especially muscle cells. This glycogen accumulation typically results in progressive skeletal muscle destruction and cardiac symptoms.
The disorder typically is classified into three types: classic infantile-onset, non-classic infantile-onset, and late onset.
Classic infantile-onset Pompe disease often is diagnosed in the first months of life. The non-classic form is likely to be diagnosed within the first year. In the late-onset form, symptoms may not begin until late childhood or even adulthood.
The type of Pompe disease an individual has helps clinicians to estimate life expectancy. Late-onset has the longest lifespan, while classic infantile-onset has the shortest, with babies, if not treated, often not living past age 2.
Pompe disease is estimated to affect 1 in 40,000 people globally, with the late-onset type occurring in about 75% of cases. In some areas of the U.S., the disease’s prevalence has been found to be as frequent as 1 in 10,000 births. The disorder was added to the recommended newborn screening program in the U.S. in 2015, which has resulted in more affected infants being identified.
Treatment for Pompe disease includes enzyme replacement therapy (ERT), with two ERTs approved in the U.S. During such treatment, a working version of the GAA enzyme — which is dysfunctional in Pompe disease patients — is administered to replace the defective enzyme and help clear glycogen from cells.
What is a Pompe disease carrier?
Pompe disease is caused by any of more than 500 possible mutations in the GAA gene, which carries instructions for making the GAA enzyme. Mutations can either lead to the production of a GAA enzyme that doesn’t work correctly or prevent the production of the enzyme.
To have Pompe disease, a person must inherit two copies of a mutated GAA gene — one from each biological parent.
Someone who has only one copy of a mutated gene is called a carrier. Carriers will not develop Pompe or have any symptoms, but may pass on the mutation to their children.
Can a baby inherit Pompe disease?
If both parents carry a disease-causing genetic mutation, there is a 25% chance that their child will have Pompe disease. There also is a 25% chance the child will not inherit any mutated copies of the gene, and a 50% chance the child is a carrier, like the parents.
If only one parent carries a disease-causing mutation in the GAA gene, none of the children will develop the disease but each child has a 50% chance of being a carrier.
Pompe disease and pregnancy
There are not many studies available on how Pompe disease can affect pregnancy, and vice versa. Thus, it is important for individuals with Pompe to discuss the risks of becoming pregnant with their healthcare team, and establish an individualized care plan.
What are the risks of Pompe disease in pregnancy?
Pregnancy can make Pompe symptoms — such as muscle weakness and respiratory problems — worse in women who have the disease. Moreover, pregnancy may cause initial Pompe disease symptoms to arise in women who have not had any symptoms until that point.
What precautions should Pompe patients take during pregnancy?
For people with Pompe disease, it is recommended that enzyme replacement therapy continue during pregnancy under the direction of the patient’s healthcare team. However, more studies are needed on this topic, given that data on the use of ERTs during pregnancy is still limited.
If possible, a multidisciplinary team of healthcare professionals should work with pregnant patients to create an individual care plan for the pregnancy and postpartum periods.
The team will discuss with the patient whether any prescribed medications should be changed during pregnancy, and keep track of any Pompe symptom changes that may occur. Care should continue after the patient has given birth.
Can pregnant patients find out before birth if their baby will have Pompe?
People with a family history of Pompe disease, or those with parents who have the disorder, may want to discuss with their doctor what their options are for learning whether their unborn baby is affected.
Diagnosis may be done through genetic testing via chorionic villus sampling — in which a sample is taken of placental tissue, usually at 10 to 13 weeks gestation. That sample will have DNA from the fetus, which can be checked for mutations in the GAA gene.
Fetal DNA also can be collected through amniocentesis, a procedure in which a sample of the amniotic sac around the fetus is taken and then tested.
Those who choose to do chorionic villus sampling or amniocentesis also should receive counseling from a healthcare professional. Such counselors will discuss the results with the expectant parents and answer any questions they may have.
Reproductive options
For patients or their partners who are carriers or have Pompe disease, there are several reproductive options to be considered before getting pregnant. These include in vitro fertilization combined with pre-implant genetic testing.
In vitro fertilization, commonly known as IVF, is when a human egg is fertilized by sperm in a laboratory setting and then tested for genetic mutations — such as in the GAA gene that causes Pompe disease — before it is implanted in the uterus. This is referred to as pre-implantation genetic analysis.
The technique allows the selection of a fertilized egg that does not have GAA gene mutations. IVF can be done with egg and sperm from the parents or from a known or anonymous donor.
Some risks, including miscarriage, multiple births, and premature birth, do accompany IVF. Thus, people with Pompe or who are carriers should talk with their healthcare team prior to IVF about the procedure’s benefits and risks, and whether it is an option for them to try to ensure their child won’t have the disease.
Prenatal therapy
The use of enzyme replacement therapy after a fetus has screened positive for Pompe disease is being studied by researchers. Initial data suggest it potentially can be an effective therapeutic option. In these cases, ERT is administered via the umbilical vein, similar to the way that intrauterine blood transfusions can be given to a fetus.
Pompe Disease News is strictly a news and information website about the disease. It does 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. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
FAQs about reproductive options if you are a Pompe disease carrier
Yes, pregnancy is possible, as Pompe disease typically doesn’t affect fertility. However, pregnancy can make Pompe symptoms worse, which means it’s important for people with the disease, or who are carriers of the disorder, to discuss the risks of becoming pregnant with their healthcare team. Enzyme replacement therapy can help slow the progression of the disease and support the body’s pregnancy-related changes.
Women who have Pompe disease have safely delivered healthy babies. However, pregnancy can make Pompe symptoms, including muscle weakness and respiratory problems, worse. People with Pompe disease who become pregnant are advised to discuss any associated risks with their healthcare team, and together establish an adequate care plan for the pregnancy and postpartum periods.
Prospective parents who have Pompe disease may first want to find out if their partner is a disease carrier, as that increases the likelihood of having a baby with the genetic disorder. In vitro fertilization — accompanied by genetic analysis to detect Pompe disease-causing mutations in fertilized eggs prior to implantation in the uterus — is an option to assure the child will not have the disease. Reproductive options should include genetic counseling about the benefits and risks.
Pompe disease life expectancy varies based on the three types of the disease that a child can inherit. Babies born with classic infantile-onset Pompe disease often do not live past age 2 without treatment. Non-classic infantile-onset Pompe disease symptoms are not as severe and, without treatment, the baby may survive into early childhood. Older-onset Pompe disease life expectancy can depend on factors such as whether the person has cardiac and respiratory issues, and how the individual responds to treatment.
Babies are born with Pompe disease when they inherit two mutated copies of the GAA gene — one from each biological parent. Both parents can be carriers of the mutated gene but not have any symptoms. Alternatively, one parent may be a person living with Pompe disease while the other is a carrier. If two people are both Pompe carriers, there is a 25% chance their baby will develop Pompe disease, and a 25% chance the baby will not. Otherwise, there is a 50% chance any children will be carriers of the mutated gene, meaning they, in turn, could pass the disorder along to their biological children.
