Wiskott-Aldrich Syndrome

At Children’s Hospital Boston, we understand how scary and overwhelming a diagnosis of Wiskott-Aldrich syndrome can be. Right now, you probably have a lot of questions: How serious is this condition? What is the best treatment approach for my child? What do we do next?

We’ve provided some general answers on these pages, and our pediatric specialists can explain your child’s condition and prognosis fully when you meet with us.

What is Wiskott-Aldrich syndrome, and what does it have to do with my child’s immune system?
Picture the human immune system as an army that constantly patrols, protects and defends the body from all types of “enemies,” including:

• bacteria
• viruses
• parasites

The immune system first takes root in a developing fetus’ bone marrow. That’s where some stem cells eventually mature into the two cell types that play the biggest role in warding off infection: T cells (white blood cells that identify and attack perceived “invaders”) and B cells (white blood cells that produce antibodies against infection).

When a child has Wiskott-Aldrich syndrome:

• his body doesn’t produce T cells
• because there are no T cells, the B cells don’t work
• his immune system is virtually nonexistent

Without a working immune system, a child with WAS has no way of warding off infections. From the time he is born, he will be at constant risk for:

• pneumonia
• eczema (atopic dermatitis)
• chronic, bloody diarrhea
• ear and sinus infections
• viral infections like herpes
• many other types of infection

These problems are further complicated by the other aspect of WAS: The child’s body does not properly produce platelets, the clotting agents that stop bleeding from getting out of control. Without healthy platelets, the child is likely to experience frequent and hard-to-control bleeding, even from the mildest bumps and scrapes. This bleeding can occur:

• under the skin
• from the nose
• from the gums and mouth
• in bowel movements

As a result of these combined deficiencies, children with WAS are also at elevated risk for developing:

• other autoimmune diseases
• anemia
• arthritis
• inflammatory bowel disease (IBD)
• nephritis (kidney inflammation)
• lymphoma, leukemia and other cancers

Is Wiskott-Aldrich syndrome treatable?
The only proven treatment for Wiskott-Aldrich syndrome is a stem cell transplant (also known as a bone marrow transplant). Because stem cells have the special ability to develop into other types of cells, a transplant can give the child’s body an essential new source of healthy white blood cells – rebuilding his immune system and allowing him to successfully ward off infections.

Although WAS is a potentially life-threatening disease, there is hope: a timely diagnosis and prompt treatment make the condition very treatable in the vast majority of cases. You and your child are in the best possible hands. 

Causes 

What causes Wiskott-Aldrich syndrome?
WAS is a genetic disorder – meaning it is caused by a mutation, or error, in the child’s genes.

WAS develops as the result of a defect in a gene located on the X chromosome. Because females have two X chromosomes, but males have only one, mothers can carry the defective gene on to their male children. As a result, WAS is a disease that almost always affects boys only.

Signs and symptoms

What are the symptoms of Wiskott-Aldrich syndrome?
Nearly every child with WAS will start showing symptoms as a baby, between the time he’s born and by the time he turns 1. The symptoms usually include:

• frequent and easy bleeding that can occur:
• from the nose
• from the mouth and gums
• in bowel movements
• frequent and easy bruising
• a small red rash consisting of “dots” under the skin (this is called petechiae)
• chronic infections
• eczema (atopic dermatitis)

FAQ 

Q: Is WAS always present at birth?
A: Yes. Since WAS is a genetic disorder (caused by an error in the genes), it is always present at birth. (Symptoms may not show up until later in his infancy, however.)

Q: Why does WAS affect boys in almost every case?
A: Wiskott-Aldrich syndrome develops as the result of a defect in a gene located on the X chromosome. Because females have two X chromosomes, but males have only one, mothers can carry the defective gene on to their male children. As a result, WAS is a disease that almost always affects boys only.

Q: How rare is Wiskott-Aldrich syndrome?
A: Very: according the National Institutes of Health, only 1 to 10 out of every 1 million boys has WAS.

Q: Is WAS a type of cancer?
A: No, it’s not. The disease is treated through the Dana-Farber/Children’s Hospital Cancer Center because of our expertise in performing stem cell (bone marrow) transplants here.

Q: Can WAS be detected during pregnancy?
A: Yes; prenatal testing can detect the gene mutation responsible for WAS. Learn how Children’s Advanced Fetal Care Center can do this.

Q: Is there any test that can detect WAS in a baby before symptoms emerge?
A: Yes: newborn screening. Learn more about newborn screening with this Children’s Hospital Boston brochure.

Q: Is the rest of my family at risk for WAS? Should my child’s siblings be screened?
A: If your child’s siblings are girls, it is very unlikely that they will also have WAS (though they can pass the mutation causing the disease on to their own sons). Because WAS is a genetic disorder, it is a good idea to ask your doctor about genetic counseling for yourself and your other children. Learn how the Genetics Program at Children’s can help.

Q: Are there different types of WAS?
A: Yes. While the majority of boys with WAS have the type known as the “classic” form, some experience a milder form of the disease known as X-linked thrombocytopenia. This is caused by a defect in the same gene involved in classic WAS, but the symptoms are much milder.

Usually, children with X-linked thrombocytopenia have platelets that are overly small in both size and number. As a result, they have trouble with easy bleeding and bruising, but do not experience the other, more severe complications.

Your treating clinician can give you specifics about the form of WAS your child has.

Q: Will my child be OK?
A: WAS is a very serious disorder that can be life-threatening. The good news is that recent advances in treatment, especially stem cell transplants and gene therapy, have made the future much brighter for children and families facing this illness.

Your child’s treatment team will give you all the information you need about his individual symptoms, recommended treatment plan and long-term outlook.

Q: If my child has WAS, does this mean he can’t be around other children, go outdoors or otherwise do anything in a non-sterile environment?
A: Any child with WAS has a severely compromised immune system and is at serious risk of developing infections. This means consistent and thorough infection control measures are a must. However, in many instances, taking simple precautions, like having your child wear a protective mask, can be enough to keep him protected before or in between more involved treatments, like a stem cell transplant.

Always ask your treating clinician for guidelines to keep your child protected from infection.

Q: How do I reduce my child’s risk of getting an infection?
A: Your child's physician will give you specific recommendations for lowering his risk of infection.

In general, families of children with compromised immune systems should take the following steps:

• follow a strict handwashing regimen for all family members and visitors
• use an air filtration system
• have the child wear a protective mask when leaving the home
• if advised by the treating clinician, administer antibiotics, antifungal or antiviral medications as a preventive measure for the child
• avoid having the child in crowds, dirty places or in the company of anyone who is ill or seems to be "coming down with something"
• watch closely for any sign of a possible infection and seek immediate medical attention

Q: How can I reduce my child’s chances of bleeding or bruising?
A: Your child's physician will provide you with specific recommendations for lowering his risk of uncontrolled bleeding or bruising. Some measures can include:

• taking corticosteroids (drugs that help prevent allergic and inflammatory reactions)
• receiving infusions of the antibody immunoglobin
• receiving platelet transfusions (this is usually only prescribed in an emergency situation)
• removing the spleen (this is usually only prescribed in an emergency situation)

Q: Is it safe for my baby to get the standard childhood vaccinations?
A: As a rule, no. Because the B-cells of children with WAS do not function properly, their bodies cannot produce the normal antibiodies that fight off viruses. Since many vaccines are actually live viruses, they pose too high a risk of infection to be safe for a child with a drastically weakened immune system. Talk to your child’s doctor for more information.

Q: Why is a stem cell transplant/bone marrow transplant the best treatment for WAS?
A: Stem cell transplants, or bone marrow transplants, work because they essentially re-create a healthy immune system. Stem cells are special cells that can mature into many different kinds of specialized cells.

In a stem cell transplant for WAS, stem cells from a donor's bone marrow are introduced into the child's system. Once transplanted, they can become white blood cells that rebuild and replenish the child's immune system.

Not every child with WAS will benefit from a stem cell transplant, but the odds of success are very good when:

• the bone marrow comes from a matched sibling (the optimal scenario) or, if this is not possible, from a parent or other family member
• the transplant takes place within the child's first few weeks to first 3 months of life

Q: If my child has a stem cell transplant, does this mean he’s cured?
A: If the transplant works – meaning the stem cells develop into normal, functional white blood cells that create a new, working immune system for your child – he may be considered cured. Many kids who undergo a stem cell transplant go on to experience a full return of healthy immune function. The younger the child is when the transplant occurs, the better the odds of being completely cured.

Q: Can my child go on to live a normal adult life, including having a family?
A: If your child's immune system is restored to good working order, he should be able to enjoy a rich, active adult life, including having a family. It is important to note, though, that genetic counseling is essential for prospective parents with a family history of WAS or any other immune deficiency.

Questions to ask your doctor

You and your family play an essential role in your child’s treatment for Wiskott-Aldrich syndrome. It’s important that you share your observations and ideas with your child’s treating physician, and that you have all the information you need to fully understand the treatment team’s explanations and recommendations.

You’ve probably thought of many questions to ask about your child’s symptoms and prognosis. It’s often very helpful to jot down your thoughts and questions ahead of time and bring them with you, along with a notebook, to your child’s appointment. That way, you will have all of your questions in front of you when you meet with your child’s treating clinician and can make notes to take home with you. (If your child is old enough, you can encourage him to write down questions, too.)
 
Initial questions to ask your doctor might include: 

• How did you arrive at this diagnosis?
• Are there any other conditions my child might have instead of or in addition to WAS?
• Does my child require further testing or procedures?
• How extensive is the damage to his immune system?
• Should my other family members be screened for WAS?
• What medications will you prescribe and what are the possible side effects?
• How can I reduce the likelihood of my child contracting an infection?
• How can I lessen my child’s risk of uncontrolled bleeding and bruising?
• Is my child a candidate for a stem cell transplant/bone marrow transplant? If yes, how soon and what are the possible risks involved?
• How should I explain my child’s condition to others?
• What other resources can you point me to for more information?