Patient education: Fragile X syndrome (The Basics)

What is fragile X syndrome? — This is a life-long condition that a person is born with. It causes learning and behavior problems, and certain body features. It can also cause certain medical problems.

Fragile X syndrome is caused by a problem with a gene on the "X" chromosome. Chromosomes are tiny parts of cells that carry the plans (genes) that make our bodies the way they are. Fragile X syndrome happens more often in boys than girls.

What are the symptoms of fragile X syndrome? — Symptoms can be different in different people. Girls with fragile X syndrome often have milder symptoms than boys. In fact, many girls have no symptoms at all. That's because girls have 2 "X" chromosomes in each of their cells, while boys only have 1. So if 1 "X" has a problem, girls still have another "X" that is normal.

People with fragile X syndrome might have the following body features:

●A head that is bigger than normal (in children)

●Crossed eyes, which is when the eyes don't line up or look in the same direction (figure 1)

●Big ears, and eyes that look "sunken in"

●Loose joints, such as in the thumbs, fingers, or wrists

●Flat feet

●Testicles that are bigger than normal (in male teens and adults) (figure 2)

Fragile X syndrome causes learning and behavior problems. Babies with fragile X syndrome can take longer to sit, walk, or talk (called "developmental delay"). Many people with fragile X syndrome have intellectual disability with a low IQ. This is more common in boys than girls.

Children with fragile X syndrome can:

●Have trouble with problem solving and organization

●Have problems with language and speaking

●Have trouble sitting still, paying attention, or making good decisions

●Feel very worried or sad

Fragile X syndrome also sometimes causes certain medical problems. These include:

●Seizures, which are waves of abnormal electrical activity in the brain that can make people pass out or move or behave strangely

●Trouble with the way the ovaries (female reproductive organs) work (figure 3)

●A tremor, which is when the hand shakes

Is there a test for fragile X syndrome? — Yes. Your doctor or nurse will do an exam, ask about symptoms, and ask whether other relatives have fragile X syndrome. They will also order a blood test to check for the abnormal gene.

Children and adults can be tested for fragile X syndrome if they have symptoms of the condition. People can also be tested for it if they have a relative who has it. Pregnant people might also choose to test their unborn baby if the condition runs in the family.

Children who are diagnosed with fragile X syndrome need further tests. These include tests to check their thinking, learning, and behavior.

How is fragile X syndrome treated? — Treatment depends on a person's symptoms and individual situation. It usually involves 1 or more of the following:

●A school plan – Depending on your child's learning problems, the school will make a learning plan for your child.

●Behavior therapy – This involves making changes at home or at school to help with your child's behavior.

●Speech, language, physical, or occupational therapy – Specialists can help with your child's language and everyday activities.

●Medicines – Some medicines help children sit still and pay attention. Others help when children feel very worried or sad. Children who have seizures are treated with anti-seizure medicines.

●Regular follow-ups with the doctor – They will do exams and tests regularly to monitor your child for medical problems that can happen with fragile X syndrome.

Should other relatives be tested for fragile X syndrome? — If you or your child is diagnosed with fragile X syndrome, let your relatives know. They should talk with their doctor about getting tested for the condition.

What if I want to get pregnant? — Talk with your doctor or nurse before you start trying. They will probably recommend that you speak with a genetic counselor (a person who specializes in genetic conditions).

How can I learn more about fragile X syndrome? — Talk with your child's doctor or nurse. The National Fragile X Foundation also has information. Their website is www.fragilex.org.

More on this topic

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Patient education: Learning disabilities (The Basics)
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Patient education: Medicines for attention deficit hyperactivity disorder (ADHD) in children (The Basics)
Patient education: Autism spectrum disorder (The Basics)
Patient education: Seizures (The Basics)
Patient education: Tremor (The Basics)

Patient education: Treatment of attention deficit hyperactivity disorder in children (Beyond the Basics)
Patient education: Autism spectrum disorder (Beyond the Basics)
Patient education: Seizures in children (Beyond the Basics)
Patient education: Tremor (Beyond the Basics)