Neurofibromatosis Symptoms & Causes

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Contact the Multidisciplinary Neurofibromatosis Program

We understand that you may have a lot of questions when your child is diagnosed with NF1:

  • What is it? 
  • What does it mean?
  • How will it affect my child?

We’ve tried to provide some answers to those questions here, and when you meet with our experts, we can explain your child’s condition and options fully.

What is neurofibromatosis type 1 (NF1)?

Neurofibromatosis type 1 is a genetic condition that can cause a variety of symptoms, including:

  • multiple flat, light-brown patches of skin pigment, called café-au-lait macules or spots
  • skinfold freckling
  • visible neurofibromas that appear as bumps on or under the skin
  • small nodules on the iris (colored part of the eye) called Lisch nodules, which do not cause problems. They’re invisible to the naked eye, but can be detected by an ophthalmologist.

What complications are associated with NF1?

Complications of NF1 vary just as much as the symptoms do. Some of the more common complications include:

  • Headaches. Children with NF1 often experience headaches. If the frequency or nature of the headaches change, you should contact your doctor.
  • Deformation of bone structure, including:
    • scoliosis (curvature of the spine). Scoliosis affects around 10 percent of individuals with NF1, and may appear in early childhood.
    • tibial dysplasia (bowing of the bones of the lower leg). This affects around 3 to 5 percent of people with NF and appears during the first year of life.
  • Optic pathway glioma. This is a thickening of the nerve connecting the eye to the brain that affects around 15 percent of people with NF1. Most optic pathway gliomas are incidental findings and don’t affect vision, cause other symptoms or need treatment.
  • Malignant changes to plexiform neurofibromas. Around 10 percent of plexiform neurofibromas may become malignant. If your child’s tumors become painful, grow suddenly or otherwise change in appearance, contact your doctor right away.
  • Issues with growth and/or puberty development. Some kids with NF1 have problems in these areas. Your child’s doctor will monitor her height, weight and development to make sure that she stays on track.

Can NF1 be cured?

Not yet. Researchers at Children’s Hospital Boston and around the world are working to gain a deeper understanding of the mechanisms behind NF1 in order to develop more effective treatments and a cure. If your child has NF1, she may be eligible to participate in one of our clinical trials.

Will my child be OK?

Most likely yes. While it’s difficult to predict the course of NF1 for any individual child, most people with NF lead healthy, productive lives.

How common is it?

NF1 is far from rare – it occurs in one in 3000 births.

What’s a neurofibroma?

A neurofibroma is a tumor that grows along a nerve in any part of the body. Usually, they look like little rubber balls under the skin, or they may protrude from the skin. They’re usually benign (non-cancerous), and most often appear during puberty and adulthood. A person with NF1 may develop only a few or more – at present, there’s no way to predict how many neurofibromas will develop.

Since neurofibromas are wrapped around nerve fibers, they can sometimes be painful if pressure is applied to them. Neurofibromas can be removed, but the surgery may leave a scar, and the neurofibroma may grow back.

Some children with NF1 may also have plexiform neurofibromas. These are a different kind of neurofibroma and generally present at birth, even though they might not be visible until later. Plexiform neurofibromas may be large, and they can encircle and interweave with normal tissue, making them extremely hard to remove. We monitor these tumors for change in size, consistency or appearance of new symptoms such as pain.

Is it cancer?

Not usually. Neurofibromatosis is characterized by tumors that are mostly benign, but in around 10 percent of individuals, the neurofibromas may have malignant (cancerous) changes.

Is NF1 ever called anything else?

Yes, you may have heard NF1 also referred to as von Recklinghausen's disease.

What’s the difference between neurofibromatosis 1 and neurofibromatosis 2?

Quite a lot – NF2 is a completely different condition:

  • It’s caused by mutations of a different gene on a different chromosome.
  • It’s much rarer, occurring in one in every 30,000 births.
  • The classic symptom of NF2 is hearing loss that begins in the teens or early twenties.

It’s extremely rare that someone would have both NF1 and NF2.

If I have NF1, is my child at additional risk for NF2?

Not at all – since they’re caused by different genes, in terms of heritability, NF1 and NF2 are completely separate.

What is segmental NF? 

Segmental NF is a form of NF1 in which symptoms are limited to a discreet part of the body. 

What’s Schwannomatosis?

Schwannomatosis is a recently-recognized form of NF that is genetically distinct from NF1 and NF2. It occurs rarely.

Who should be screened for NF1?

You should be screened for NF1 if you and/or your child have:

  • a family history of NF1 and/or
  • multiple brown skin spots, bumps on or under the skin, and/or Lisch nodules
  • a crooked arm or leg bone 

Follow-up care will depend on the type and complexity of symptoms, and will be individualized for each person.

How reliable is genetic testing for NF1?

Unfortunately, genetic testing isn’t perfect. In the vast majority of people who show two or more symptoms of NF1 – around 95 percent – genetic testing can identify a mutation. But that means that five percent of people with NF1 will not have a mutation that is identifiable by the testing that is currently available.

As a result, if your child tests negative for a NF1 mutation, there’s still a chance that she could have NF1, and should still be followed if she has at least one known symptom of the condition. Please remember that the results from genetic tests should always be discussed with your doctor or genetic counselor.

Causes

What causes neurofibromatosis 1?

Inheritance of NF1

NF1 is an “autosomal dominant” gene. This means that:

  • Even though each child inherits two NF1 genes (one from each parent), if only one of them has a mutation, the child will have the condition.
  • If a parent has the mutation, there is a 50% chance that any child of theirs can have it, too.
  • It affects males and females equally.

When neurofibromatosis is not inherited

Around half of all individuals with NF1 are the first in their family to have the condition. This usually means that the condition wasn’t inherited from a parent, but instead is the result of a spontaneous mutation of the NF1 gene.

But I thought you said that NF1 was genetic?

It is – it’s a common misconception that “genetic” always means “inherited.” In fact, “genetic” only means “caused by a gene,” which can (and often does) mean that a gene is inherited, but it can also mean that the gene mutated spontaneously by itself.

Other causes

There has been absolutely no evidence that NF1 is caused by any environmental agents or by anything that the mother did during pregnancy.

Signs and symptoms

What are the symptoms of NF1?

NF1 can affect different areas of the body and many of the features are age-dependent. In order to be diagnosed with NF1, your child must have at least two of the following symptoms:

Symptom

 

General age of appearance

parent or sibling with NF1

 

present at birth

specific abnormality of arm bone (radial dysplasia) or leg bone (tibial dysplasia)

 

present at birth (but may not be identified until later)

six or more café-au-lait macules

may be present at birth, often the first sign to appear

 

optic pathway glioma (non-cancerous thickening of the optic nerve)

 

N/A. Since doctors don’t regularly screen for these, they’re usually detected when other signs and symptoms of NF appear.

 

freckling in the armpit, groin or neckfolds

 

seen in 90% of children with NF1 by age 6

Lisch nodules (small spots on the iris of the eye that do not affect vision. They aren’t visible to the naked eye, but an ophthalmologist would be able to detect them.)

 

seen in 95% of young people with NF1 by age 20

two or more neurofibromas or one plexiform neurofibroma

 

Plexiform neurofibromas are present at birth, but may not be identified until later. Non-plexiform neurofibromas usually appear during the teenage and adult years.

 

Keep in mind that any of these symptoms – even neurofibromas and plexiform neurofibromas – can also appear in people who don’t have NF1.

It’s also important to remember that two people in the same family can both have NF1 but experience different symptoms and levels of severity. It’s impossible to predict how anyone’s NF1 will progress, even by looking at a family member who also has the condition.

FAQ

Q:  Will my child be OK?
A:
Most likely yes. While it’s difficult to predict the course of NF for any individual child, most people with NF lead healthy, productive lives.

Q:  Is there a test for NF1?
A:
Yes, but it’s not perfect. In patients who already have at least two of the typical clinical signs, genetic testing can identify the mutation that causes NF1 about 95 percent of the time. But because there’s a 5 percent chance that your child may test negative but still have NF1, if she has clinical signs, we will follow her closely regardless of her test result.  

Q:  When will I know whether my child has NF1?
A:
It’s hard to say for sure when a child’s symptoms will develop. But we know that 80 to 85% of patients with NF1 are diagnosed by age 6, and 95% are diagnosed by age 8. So if your child is older than 8 and hasn’t developed enough symptoms to be diagnosed, the likeliness of her having NF1 drops dramatically.

Q:  If there’s some uncertainty as to whether my child has NF1, why wouldn’t I just ask for a genetic test?
A:
Most of the time, the results of the test don’t matter in a practical sense, because they won’t necessarily change how we approach your child’s care. Since there’s a 5% chance that the test won’t identify a mutation, as long as she shows clinical signs, we’ll follow her, just to be safe.

The tests are also expensive, and not all insurance companies and plans may cover the cost of all the testing that’s needed to make a diagnosis.

That said, some parents choose to have the test anyway. Your doctor or genetic counselor will be happy to discuss all of your options with you.

Q:  Is it possible to know whether my child has NF1 without doing genetic testing?
A:
Definitely – in fact, NF is most often diagnosed clinically, and many patients with NF never undergo genetic testing. 

Q: Are neurofibromas contagious?
A:
Not at all. NF1 is a genetic disorder, meaning that if your child has it, it was already in her genes when she was born. Neurofibromas don’t “spread” from person to person.

Q: Isn’t neurofibromatosis what the Elephant Man had?
A: No. While scientists thought this was so for many years, in 1986 it was established that Joseph Merrick, the so-called “Elephant Man,” actually had an extraordinarily rare condition called Proteus syndrome.

Q: Are there any dietary modifications that might help my child?
A:
Aside from the benefits that a healthful diet, exercise and vitamins offer to everyone, there’s no evidence that they affect the growth of neurofibromas or the progression of neurofibromatosis.

Q:  Did I do anything to cause my child’s neurofibromatosis?
A:
No. There is nothing you did (or didn’t do) before or during pregnancy, or after your child was born, that could have caused NF1.

Q: Are the clinical problems treatable?
A:
Yes, and your child should be cared for by NF1 specialists who are familiar with treating the condition in children.

Q:  Can we predict how my child’s condition will progress?
A:
Unfortunately, NF1 is highly unpredictable. At this time, it’s very difficult to predict whether your child’s symptoms will be mild, moderate or severe. Severe complications are rare.

Q: Is there anything else that can cause these symptoms?
A:
Yes, there are some other rare conditions. The doctor will keep them in mind during your child’s visit, and test for them if they seem to be a possibility.

Q: If my child has many café-au-lait spots, does that mean that she will develop very severe NF1?
A: Not necessarily – there’s no connection between the number of café-au-lait spots and the severity of NF1.  

Q: If my child has many café-au-lait spots, does that mean that she’ll develop many neurofibromas?
A:
No, all factors of NF1 are independent:

  • Many spots don’t mean many neurofibromas.
  • Having a spot doesn’t mean that a neurofibroma will grow on that spot.
  • A parent and child can both have NF1 but different symptoms and degrees of severity.

Q: Is inherited NF1 more severe than NF1 from a spontaneous mutation?
A:
No, there’s no correlation between how your child came to have NF and how mild, moderate or severe her symptoms may be. 

Q: Could I have another child with NF1?
A:
Yes, because anyone can have a child with NF1. If you have a mutation in the NF1 gene, there’s a 50 percent chance that another child will have the mutation. If you don’t have the mutation, there’s about a 1 percent chance that another would have NF1, too.

Q: Is there any way to know whether I will have another child with NF1?
A:
Prenatal diagnosis is available, although it is not possible to know what symptoms of NF1 a child may have. Talk to your genetic counselor for more information and to discuss testing options in more detail.

Q: Should my other children be tested for NF1?
A:
If your other children have any signs of NF1, they should be evaluated.

Q: Is it possible to have NF1 and not know it?
A:
It’s certainly possible to have NF1 and have symptoms that are so mild that the person thinks nothing of them. In fact, although it’s rare, a parent may learn that he or she also has NF1 when his or her child is diagnosed.

Q: Should the parents be evaluated for NF1?
A:
Yes, if the parent is showing signs or symptoms of NF1.

Q: Will my child be able to have children?
A:
Most likely - NF1 doesn’t affect fertility in males or females.

Q: If my child becomes a parent some day, will his children also have NF1?
A:
As with anyone with NF1, there’s a 50% chance that his or her child will also have the condition.

Questions to ask your doctor

After your child is diagnosed with neurofibromatosis, you may feel overwhelmed with information. It can be easy to lose track of the questions that occur to you. Lots of parents find it helpful to jot down questions as they arise – that way, when you talk to your child’s doctors, you can be sure that all of your concerns are addressed.

If your child is old enough, you might suggest that she write down some questions to ask her health care providers, too.

Always ask questions about unfamiliar words– feel free to interrupt your child’s doctor to ask what something means, or at any time when you don’t understand something. We know it’s a lot to take in at once, and want to make sure you understand everything you need to. 

Other questions include:

  • Can you give me a list of possible problems I should check for, including behavioral, physical and educational issues?
  • What aspects of my child’s health and behavior should I be paying attention to?
  • How can I explain this to my friends, family and doctors?
  • What should I be doing now?
  • Which care providers should my child see, and how often?
  • What medications will you prescribe, if any? What are the possible side effects?
  • Does anything need to change in my child’s home, school or social life?
  • Are there any resources you recommend for more information?

Teens and NF1

It can be hard enough to be a teenager without having to deal with a chronic condition like NF1. This is usually when neurofibromas tend to develop, and this can be very upsetting for someone who may be beginning to take a special interest in her appearance. Understandably, both parents and teens want to know when – and how many – neurofibromas will show up, but this is impossible to predict.

There’s also been some evidence that at times of hormonal changes, such as puberty or pregnancy, more symptoms of NF1 may develop. Understanding what your child is going through can help you support her during this important time - and help you cope, too. Your teen may:

  • be exploring her own identity - figuring out who she is, what’s important to her and how she can incorporate her condition into how she sees herself and her place in the world
  • have a strong desire to feel “normal” and not have anything that makes her feel different from her peers
  • resent the need for close monitoring of her health

Here are some ways you can help:

  • Encourage your child to talk openly with you. Keep your initial focus on listening to what she’s saying, and making sure you understand what she means. Sometimes what a teen needs most is simply to feel understood.
  • Include your teen in decisions about her health care as early as appropriate.
  • Encourage your child to find peer support among other NF1 patients. This can decrease her sense of being “different,” and reassure her that what she’s going through is normal.     
  • Help your teen to set long-term academic and vocational goals.
  • Teens like to feel like active contributors to the family. Encourage your child to do chores and care for younger siblings. Sibling support is also important.
  • If appropriate, help your teen identify a trusted adult she can talk with about issues that she may not be comfortable talking to members of her family about.
  • Support her efforts to develop and sustain friendships and other social relationships.

Make sure that your teen knows that there are lots of ways to meet – and have fun – with other teens with NF, including summer camps, such as Camp New Friends offered through Neurofibromatosis Inc or the Children’s Tumor Foundation’s NF Summer Camp. CTF also runs a weekly youth-moderated online chat room through a program called YouthCONNECT for kids aged 10-17 who have NF or have a sibling or friend with NF.

NF1 and learning disabilities

Up to half of all children with NF1 have some kind of learning disability, which range from mild to severe. True intellectual disability is rare. And just because a child has difficulties with learning doesn’t mean she’s not smart – it’s been generally shown that the problem with learning disabilities isn’t a lower IQ, but an issue with one or more of the following:

  • working memory
  • attention
  • focus
  • visual-motor function (dexterity, fine-motor control)
  • spatial orientation (awareness of the body in space)

It’s also widely accepted that the earlier a learning disability is identified, the more effective treatment and compensatory measures tend to be. That’s why we recommend that if your child has had some delayed development (such as with sitting, walking or talking), or if there’s been any suggestion of learning issues at school, you should:

  • Ask that your child be evaluated by her school for a learning disability – if a learning disability is identified, the school can then put together an Individualized Education Plan (IEP) for your child to identify and help her meet her educational goals.
  • Consider comprehensive neuropsychological testing for your child. Typically, schools do intelligence and basic achievement testing, but they lack the resources to pull out the level of detail that a specialist can provide. If possible, your child should be evaluated by a neuropsychologist who has experience in testing children with NF1.

Can learning disabilities get worse with time?

No, although it might sometimes look that way. Since different things are asked of children at different levels of their education, issues may surface that hadn’t yet been identified. For example, your child may easily learn to read, but have some difficulty when it comes time to interpret what she has read.
 

When resources are available to help my child succeed?

Luckily, there has been lots of research into how kids with different kinds of learning disabilities can learn best. Your child’s IEP team will work with you to develop a plan that’s been customized for her, but adjustments that the school might make could include

  • giving your child extra time on tests
  • assigning a tutor to work with her
  • having her sit closer to the front of the room

Like all children, kids with NF1 have strengths and weaknesses; and like all children, helping them succeed is just a matter of capitalizing on their strengths and compensating for their weaknesses.

Center for Young Women’s Health and Young Men’s Site

Young men and young women may have some concerns specific to their gender, and some that they share. At Boston Children’s, the Center for Young Women’s Health and Center for Young Men’s Health offer the latest general and gender-specific information about issues including fitness and nutrition, sexuality and health, health and development and emotional health.

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