Fabry Disease in Children

Fabry disease is a progressive disorder. An enzyme deficiency results in the build-up of GL-3 in cells throughout the body. This build-up starts early in life and continues over decades. So, even though children with Fabry disease may not yet experience serious symptoms, damage is already starting to occur.

The symptoms children do face may be easily overlooked or mistaken for other, more common diseases. Missing gym class because of heat and exercise intolerance, painful hands and feet, and embarrassing frequent trips to the restroom due to gastrointestinal issues are just some of the many physical challenges children with Fabry disease may face.

If a child has not yet been diagnosed, these problems may be compounded by the frustration of not knowing what's wrong. Childhood symptoms can sometimes be dismissed as growing pains, psychosomatic problems, or even laziness.

Intervention by an informed physician can lead to a definitive diagnosis for children with seemingly unrelated and troubling symptoms, as well as identification of other family members who may be suffering from the disease.

After Diagnosis

After a diagnosis is made, it can be important for a child and his or her family to feel empowered with information about Fabry disease, since they may find that they need to educate school nurses, gym teachers, or camp counselors about the disease. Your doctor or a genetic counselor may be able to help you think through how to explain this rare, complex disorder. Some important points you may want to include are:

  • Fabry disease is a genetic condition
  • Fabry disease is not contagious
  • He/She may have sudden episodes of intense pain (usually in the hands and feet)
  • He/She may have frequent episodes of fatigue
  • Weather changes and/or physical activity may bring on fevers or pain episodes

Understandably, children living with this chronic, progressive disease may experience a range of psychosocial issues, including anger, resentment, depression, fear, and feelings of isolation. A genetic counselor or hospital social worker can help direct children and their families to support services, advocacy groups, and other resources.

Children and their families may take comfort in knowing that although the disease is rare, there are others in similar situations. The Resources page lists patient advocacy and support groups.

If your child has Fabry disease, talk to his or her doctor about the right time to start treatment. The safety and effectiveness of Fabrazyme in patients ages 8 to 16 is similar to the safety and effectiveness seen in adults. Sixteen pediatric patients ages 8 to 16 were included in clinical studies of Fabrazyme. Patients younger than 8 years of age were not included in clinical studies so the safety and effectiveness of Fabrazyme in this age group has not been established.

Indication and Usage

Fabrazyme® (agalsidase beta) is used to treat patients with Fabry disease. Fabrazyme lowers the amount of a substance called globotriaosylceramide (GL-3), which builds up in cells lining the blood vessels of the kidney and certain other cells.

The lowering of GL-3 suggests that Fabrazyme may improve how Fabry disease affects your body; however a relationship of lower GL-3 to specific signs and symptoms of Fabry disease has not been proven.

Important Safety Information

Fabrazyme can cause serious side effects, including:
Severe Allergic Reactions (anaphylaxis): Life-threatening severe allergic (anaphylactic) reactions have been seen in patients during Fabrazyme infusions. Approximately 1% of patients who have received Fabrazyme either during a clinical study or after Fabrazyme was approved have experienced anaphylactic or severe allergic reactions during their infusion.
  • These reactions have included: localized swelling of the face, mouth and throat, narrowing of breathing airways, low blood pressure, hives, difficulty swallowing, rash, trouble breathing, flushing, chest discomfort, itching and nasal congestion.
  • People who have experienced these reactions have required treatment including heart/lung resuscitation, oxygen, fluids given through the vein, hospitalization, and have needed treatment with inhaled drugs called beta-adrenergic agonists to help open the breathing airways, antihistamines, epinephrine (also known as adrenalin), and a medication given through the vein called a corticosteroid (or steroid) which helps to decrease the body’s allergic reaction by decreasing inflammation.
  • If you experience a severe allergic or anaphylactic reaction, your healthcare professional will immediately stop the infusion of Fabrazyme and provide you the necessary emergency medical treatment. Because of the possibility that severe allergic reactions may occur, appropriate medical support should be available during your Fabrazyme infusion.
Infusion-Associated Reactions: In clinical studies with Fabrazyme, 59% of patients experienced infusion-associated reactions during Fabrazyme administration, some of which were severe.
  • For patients who have had reactions to their infusions, it is recommended that they be given anti-fever and antihistamine medications right before their next infusions. Infusion-associated reactions have happened in some patients even after taking these medications before their infusions.
  • If an infusion reaction occurs, slowing the infusion rate, stopping the infusion for a short time and/or giving more anti-fever and antihistamine medications and or steroids may improve the symptoms.
  • If severe infusion-associated reactions happen, your healthcare professional should consider stopping the Fabrazyme infusion right away and should provide medical care for your condition. Severe reactions are generally managed by giving antihistamine medications, corticosteroids, fluids through the vein, and/or oxygen when needed. Because severe infusion-associated reactions may happen, medical treatment should be readily available during your Fabrazyme infusion.

Pre-existing Heart Problems: People with advanced Fabry disease may have heart problems, which may put them at a higher risk for severe complications from infusion-associated reactions. These patients should be watched closely during their infusion if the decision is made to give them Fabrazyme.

Immune Response and Continued Treatment After Allergic Reaction: In the clinical studies, a few patients developed IgE antibodies or a reaction to an allergy skin test specific to Fabrazyme. IgE antibodies are usually produced by the body’s immune system during an allergic reaction. Your doctor should consider testing for IgE antibodies if you experience suspected allergic reactions. Providing Fabrazyme to patients who have experienced severe or serious allergic reactions to Fabrazyme should only be done after carefully considering the risks and benefits of continuing the treatment, and only under the direct supervision of a qualified healthcare professional and with appropriate medical support readily available.

Common and Other Possible Side Effects:
  • Common side effects reported in 20% or more of Fabrazyme treated patients in clinical studies compared to placebo were upper respiratory tract infection, headache, cough, burning and/or tingling sensation, fatigue, dizziness, swelling in the legs, and rash.
  • Serious and/or frequently occurring side effects (occurring in 5% or more of the patients) thought to be related to Fabrazyme in placebo-controlled and open-label clinical studies have included: chills, fever, feeling hot or cold, trouble breathing, nausea, flushing of the skin, headache, vomiting, burning and/or tingling sensation, fatigue, itching, pain in the hands and feet, high blood pressure, chest pain, throat tightness, abdominal pain, dizziness, rapid heart rate, nasal congestion, diarrhea, swelling in the legs, muscle pain, back pain, paleness of the skin, slow heart rate, hives, low blood pressure, face swelling, rash and sleepiness.
  • Other serious side effects that were seen in the clinical studies included stroke, pain, lack of muscle coordination, slow or irregular heartbeat, stopping of the heartbeat, decreased blood pumped by the heart, dizziness, and kidney problems resulting in too much protein leaving the body in the urine (nephrotic syndrome). These side effects also occur as part of Fabry disease.
  • Since Fabrazyme has been approved, there have been side effects that resulted in death that may or may not be related to the use of Fabrazyme. These included: the heart and/or lungs stop working (known as cardiorespiratory arrest, respiratory failure, and/or cardiac failure), life-threatening infection in the blood stream (known as sepsis), stroke, heart attack, kidney failure, and pneumonia. Some of these side effects were reported in Fabry disease patients with significant underlying disease.

The safety and effectiveness of Fabrazyme in patients younger than 8 years of age have not been studied.

Please see full prescribing information for Fabrazyme.