Answers to questions families often have about caring for their child with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is a genetic disorder of the nervous system which can cause tumors to form on the nerves anywhere in the body at any time resulting in a variety of medical problems, primarily affecting the skin and nervous systems. This progressive disorder affects all races, all ethnic groups and both sexes equally. NF1 is one of the most common genetic disorders in the United States (approximately 1 in every 2,500 to 3,000 births).

NF1 is an autosomal dominant genetic condition; it is not contagious. Approximately 50% of those affected with Neurofibromatosis NF1 have a prior family history of NF1. The other 50% of cases are the result of spontaneous genetic mutations, which was not due to anything the parents did before or during the pregnancy. Typically if an individual does not have NF1, he or she can not pass it on to his or her children. The NF-1 gene is located on chromosome 17.

NF1 can cause a variety of symptoms affecting multiple organ systems. The condition can be very different from person to person even within families. The “coffee-with-milk” (Café-au-lait) spots are the hallmark finding of NF1 and as mentioned above are one of the diagnostic criteria. In addition to the diagnostic criteria mentioned above, other symptoms may include:

• Learning disabilities
• Large head
• Short stature
• Scoliosis
• Decreased bone mineral density
• High blood pressure
• Pain
• Rare malignant tumors (e.g., malignant peripheral nerve sheath tumors, rhabdomyosarcoma, juvenile myelomonocytic leukemia)
• Cerebrovascular abnormalities (problems with blood vessels that can lead to stroke)

Diagnostic criteria for NF require 2 or more of the following:

• Six or more Café-au-lait spots 1.5 cm or larger in post-pubertal individuals, 0.5 cm or larger in pre-pubertal individuals
• Two or more neurofibromas of any type (benign tumors of primarily the nerves mostly observed on the skin) or 1 or more plexiform neurofibroma (larger and more diffuse)
• Freckling in the axilla or groin
• Optic glioma (tumor of the optic pathway that can lead to visual loss)
• Two or more Lisch nodules (benign iris hamartomas)
• A distinctive bony lesion; e.g., anterolateral bowing of the leg that fractures and does not heal, and dysplasia of a skull bone (sphenoid wing)
• A first-degree relative with NF1

The majority of individuals with NF1 do not have major medical problems. A small portion of individuals will have serious problems that can be difficult to treat but will require medical treatment. Even within families, different family members can have different symptoms. The vast majority of individuals with NF1 can complete schooling of various levels, hold jobs, and live independently. Significant cognitive impairment is not common.

NF1 is an autosomal dominant condition. This means that an individual with NF1 would have a 50% chance of having a child with NF1 for each pregnancy.

There is no known cure for NF1, although the gene for NF1 has been identified. However, there are treatments for many of the manifestations of NF1.

The variability of prognosis is reflected in the impact on the family. Most children with NF1 will have no significant medical problems and can be expected to transition easily into adulthood and independence. Some children will have complications requiring surgery or medical treatments and some will have impairments in learning that could affect their educational attainment and ability to support themselves financially.

No. This is a common misconception. Joseph Merrick, referred to as the "Elephant Man," was initially thought to have a severe presentation of NF1. Experts now think that he had an entirely different condition called Proteus syndrome, which involves massive overgrowth and hypertrophy, hyperostoses, and lipomas.