Neurofibromatosis: Overview

What is neurofibromatosis (NF1)?

The Neurosciences Institute at Children's Hospital Colorado
Neurofibromatosis type 1 (also known as NF1 or "von Recklinghausen disease") is a genetic condition. It causes non-cancerous growths (tumors) to develop on any nerve ending throughout the body. NF1 is hereditary and runs in families. Symptoms usually appear in childhood.

The severity of neurofibromatosis can range from having very few signs or medical concerns to having many signs with significant long-term medical issues.

What’s the difference between NF1 and NF2?

NF1 is a distinct condition from neurofibromatosis type 2 (NF2), with different signs and symptoms. Although both conditions have similar names, an individual with NF1 is not at risk of developing NF2.

What causes neurofibromatosis?

NF1 is caused by a change (mutation) in the NF1 gene on chromosome 17. Each person has two copies of this gene, with one copy inherited from each parent. Normally, the gene prevents too much growth in cells for certain body parts. If one copy of this gene is altered due to a random error or mutation, it cannot function correctly. This ultimately leads to signs of NF1.

Neurofibromatosis is inherited in an autosomal dominant manner, meaning each child of an affected individual has a 50% chance to develop NF1.

Who gets neurofibromatosis?

NF1 is common, occurring in about 1 in 3,000 births. It affects males, females and all ethnic backgrounds equally. However, no two patients with the same NF1 gene mutation are necessarily affected in an identical manner. Even two individuals in the same family can be affected to different degrees, for reasons that doctors don’t yet understand.

In approximately half of patients with NF1, the genetic mutation is inherited from a parent who also has symptoms, although they may be mild and undiagnosed. If a parent is affected, each of his or her children has a 50% (or 1 in 2) chance to inherit the gene mutation and develop NF1. All individuals with an NF1 gene mutation will develop signs of NF1, although we cannot predict which signs, when they might develop or the severity.

In the other half of patients with NF1, the gene change occurred sporadically, meaning no other relatives have the condition. There is a small chance of germline mosaicism, meaning the genetic change happened only in the parent’s egg or sperm cells, and the parent does not actually have signs of NF1.

Resources for neurofibromatosis and non-cancerous tumors

  • The Neurofibromatosis Program at Children’s Hospital Colorado
  • Children’s Tumor Foundation offers information about life with NF and research funding.
  • GeneTests Medical Genetics Information provides information about genetic conditions and links to support information.
  • Neurofibromatosis Network  is an advocacy group that supports NF research.
  • National Institute of Neurological Disorders and Stroke provides medical information about the condition.