Genetics Northern California

Neurofibromatosis 1

What is neurofibromatosis, type 1 (NF1)?
How common is NF1?
What causes NF1?
How is NF1 diagnosed?
How is NF1 treated?
Where can I get more information about NF1?

What is neurofibromatosis, type 1?
Neurofibromatosis, type 1 (NF1) is a genetic condition that mainly affects the skin and nerves. The most common features are cafe-au-lait spots (darker spots on the skin) and neurofibromas (small benign lumps) on or under the skin. There can also be freckles in the armpits and groin areas, and small bumps on the iris (the colored part of the eye). Most people with NF1 have few medical problems related to their condition. However, the course of NF1 is unpredictable, and varies from one person to another.

NF1 is the most common type of neurofibromatosis. Other types of NF, such as NF2 and schwannomatosis, are rare conditions with different symptoms and causes.

Medical concerns in NF1
Most people with NF1 do very well, and do not have major medical problems.  However, some medical concerns related to NF1 include:
 - Deformities of the bones at birth
 - Spine problems
 - High blood pressure 
 - Benign tumors in the brain or on the spine
 - Optic glioma (a tumor of the nerve to the eye) 
 - Increased risk for cancer

Learning and behavior in NF1
Most individuals with NF1 have normal intelligence, but learning disabilities and behavior concerns are common. This can include verbal and non-verbal learning disorders, attention deficit hyperactivity disorder (ADHD), and problems with coordination.

How common is NF1?
NF1 affects about 1 in every 3,000 people, but symptoms are not usually present at birth. 

What causes NF1?
Neurofibromatosis 1 is caused by a genetic change (mutation) in a gene called NF1, located on chromosome 17.

NF1 is an autosomal dominant condition. This means that NF1 affects males and females the same, and a person with NF1 has a 50% chance to pass the gene mutation to a child. About half the time, a person diagnosed with NF1 has a parent with the condition. However, NF1 can happen for the first time in a family because of a new genetic change, called a "de novo” mutation. This random change happens when the sperm or egg cell is being formed. In these families, neither parent has NF1.

How is NF1 diagnosed?
The diagnosis of neurofibromatosis is often made in childhood when the common skin findings first appear.  For most people, the diagnosis is based on having at least two of the following features:
1. Six or more cafe-au-lait spots
2. Two or more neurofibromas
3. Freckles in the areas of the armpit or the groin
4. An optic glioma (a tumor of the optic nerve)
5. Lisch nodules ("freckles" on the iris of the eye)
6. Sphenoid dysplasia or tibial dysplasia (A specific kind of bone problem)
7. A parent, child, or sibling with NF1

Genetic testing - Genetic testing is not usually needed to diagnose NF1. However, it may be considered when a diagnosis is uncertain or for family planning.

How is NF1 treated?
Regular medical care is recommended to watch for problems that could happen with NF1. No one can predict which children with NF1 will develop problems, or which problems they will have. Since every case of NF1 is different, treatment depends on which symptoms develop. There is no cure for NF, but treatments and therapies can address many of the problems that may arise. Kaiser Permanente in Northern California provides specialty care for people with NF1 at the Regional Neurofibromatosis Program.

Overview of NF1 Medical Care
• Eyes/Vision: It is important for children with NF1 to have a yearly check-up with a pediatrician, and a yearly eye exam by an Ophthalmologist. Visits to a specialist may also be necessary. About 10% or people with NF1 have a thickening or tumor of the optic nerve, the nerve that connect the eyes to the brain. Since optic gliomas can impair vision, children with NF1 should see an ophthalmologist yearly. Most optic gliomas are just routinely monitored, and do not need treatment.

• Skin: Neurofibromas on the skin may be removed by a plastic surgeon or dermatologist, but it is possible they may grow back. If a neurofibroma develops in a painful or inconvenient location, surgical reduction of the tumor may be possible. It may be difficult or impossible to remove a deep plexiform neurofibroma.

• Bones: A curve in the spine, called scoliosis, is more common in people who have NF1, so periodic X-rays and physical examinations are important. A spine fusion may be necessary if the scoliosis progresses rapidly. If defects of the bone are present, orthopedic surgery may be necessary.

• Learning: Because many people with NF1 have learning disabilities, special accommodations may be requested at school or work. Evaluation by a neuropsychologist can be useful in determining whether a person has a learning disability and what type of learning issues are present.

• Speech and coordination: Difficulty with speech can occur with NF1, and ADHD is more common in those who have NF1. People with NF1 may be less coordinated in physical activity and skills such as handwriting. Specific therapies, such as speech therapy, physical therapy, and occupational therapy, can be helpful in dealing with these issues.

• Blood Pressure: Routine blood pressure checks are necessary for all individuals with NF1 to detect hypertension and problems with blood vessels.


Where can I get more information about NF1?
NIH: Genetics Home Reference on NF1 - General information about NF1 provided as a service of the U.S. National Library of Health. Links to many related sites are included on the page. https://ghr.nlm.nih.gov/condition/neurofibromatosis-type-1

GeneReviews:Neurofibromatosis 1– Detailed information about NF1 intended for medical professionals.  https://www.ncbi.nlm.nih.gov/books/NBK1109/

Family Support Resources
Children’s Tumor Foundation: http://www.ctf.org/
Neurofibromatosis Network: https://nfnetwork.org/ 

Last reviewed: February 6, 2018
Reviewed by: Kimberly Barr, MS, LCGC