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About Neurofibromatosis

Neurofibromatosis (NF) is a genetic disorder that causes tumours to grow on certain nerves. It can also cause deafness, chronic pain, as well as bone and cardiovascular defects and learning disabilities.

NF encompasses three distinct disorders: NF1, NF2, and schwannomatosis. NF1 effects about 1 in 3,000 people, while NF2 and schwannomatosis both effect about 1 in 40,000.

There is currently no effective drug treatment for NF.

Features of NF1

The signs of NF1 usually begin to appear in childhood or adolescence. If two or more of the following signs are present, a diagnosis of NF1 is confirmed:

  • Family history of NF1
  • 6 or more light brown (cafe-au-lait) spots on the skin
  • Presence of pea-sized bumps (neurofibromas) on the skin
  • Larger areas on the skin that look enlarged (plexiform neurofibromas)
  • Freckling under the arms or in the groin area
  • Pigmented bumps on the eye's iris (Lisch nodules)
  • Skeletal abnormalities such as bowing of the legs, curvature of the spine (scoliosis) or thinning of the shinbone
  • Tumor on the optic nerve (optic glioma) that rarely interferes with vision

Click here for a graphical summary of the symptoms of NF1.

NF1 is a complex disorder, in which a number of diverse features may occur. Moreover, one of its hallmarks is diversity of clinical expression from one person to the next—some are quite severely affected, while many are not. There does not seem to be any way to predict severity or specific complications. No medical test provides such predication, and the condition even varies from person to person in the same family.

Overall, we estimate that NF1 causes mild manifestations in about 2/3 of affected individuals. Do not be misled by newspaper or magazine articles, or television programs that depict NF1 as invariably severe. NF1 can produce severe complications, but, fortunately, these are rare. Unfounded assumptions that a child has a serious medical disorder can do just as much harm as overlooking the medical condition. Please keep in mind that people with NF1 generally enjoy good health.

Psychological and social issues

NF can be stressful for those affected. Some may experience social isolation and loneliness. Uncertainty about possible future complications of the disorder, decisions about whether to tell friends and whether to have children are concerns expressed by many. Anxiety about the need for medical treatment, a sense of losing control and the feeling of being different from others are often experienced. The general public's reaction to disfigurement and the unfounded fear that NF is contagious can provoke unpleasant situations.

NF NZ is available to help those with NF overcome their sense of isolation and offer an opportunity to share feelings and to learn more about the disorder in an atmosphere of mutual support and understanding.

Adjustment of the child and family

Because of the variability of features, some children with NF1 are obviously affected, whereas others are not. It is important that the parents of a child with NF know how much the child understands about his or her condition. How much and what to tell a child must be individualized to the child's condition, maturity and level of understanding. If there is any rule of thumb it is that a child old enough to ask questions is old enough to be given honest answers at a level appropriate to their maturity.

Children with the rare disfiguring complications of NF1 may be subject to questions or teasing from classmates. This requires a high level of sensitivity, both to the child and to the rest of the class.

Individuals with NF1 face a lifetime of experiencing the unfairness that results from ignorance. It is never too soon to remedy that with age-appropriate, but accurate information. This is where the NF NZ support group may help.

Genetics of NF

NF is caused by a single, "dominant" gene. This gene may be inherited from an affected parent, or it may occur by chance in an individual with no family history of NF1 as a result of a gene change called a spontaneous mutation.
About half of those with NF1 have inherited it from a parent; the other half are affected because of a spontaneous mutation and have no affected parent. It is believed that NF has an unusually high spontaneous mutation rate, which means that NF1 can appear in any family.

Once an individual has the NF1 gene, whether by inheritance or because of a spontaneous mutation, there is a 50-50 chance, each time he or she has a child that the gene will be passed on. There is also a 50-50 chance each time that the gene will not be passed on. In this case, the child will be completely free of neurofibromatosis and will never develop signs of the disease. This is just like flipping a coin: the odds are 50-50 every time. Almost every individual who has the gene will show some signs of NF1.

NF1's extreme variability is seen even within families. The same gene present in different members of the same family—brothers and sisters, grandparents, parents and children—can result in NF1 cases of widely varying degrees of severity and with very different NF1 symptoms. For example, a parent who has mild NF1 (few cafe-au-lait spots or neurofibromas) may have a very severely affected child. The reverse situation can also occur: a severely affected parent may have a child with very mild NF1. At present, there is no way to predict how seriously affected any person in any family with NF1 will be, or which NF1 complications he or she will develop.

Help With Making the Decision

Genetic counselling can help couples to work through the decision-making process. Genetic counsellors do not tell anyone what to do; they provide information, clarify issues, and can also explain possible alternatives such as adoption or artificial insemination. In this way, the couple is encouraged, with the support of the counsellor, to arrive at a decision that is right for them.