A syndrome that can affect nearly all parts of the body including the brain, spinal cords, nerves, skin, and several body systems is known as a syndrome called Neurofibromatosis shorted as NF (GARD 1). The syndrome is accompanied by tumors called neurofibromas that grow along nerves in a person’s body or under the skin. As the tumors size increase they can press on vital areas of the body, causing problems in the way the body functions. There are two types, NF1 and NF2. NF1 is more common, occurring in 1 of every 3,000 births and affecting an estimated 100,000 Americans, it is also known as von Recklinghausen disease (GARD 1).
NF2 is rarer, seen in 1 in 25,000 births; people with NF2 usually develop benign tumors on the nerves in their ears, causing hearing loss, eventual deafness, and problems with balance (GARD 1). Although type 1 is more prevalent both NF1 and NF2 carry the same signs and symptoms. Both types of neurofibromatosis are autosomal dominant genetic disorders, which means an affected person has 1 chance in 2 of passing it on with each pregnancy (Sharp 1). Neurofibromatosis also can be the result of a spontaneous change (mutation) in the genetic material of the sperm or egg at conception in families with no previous history of NF.
About half of cases are inherited, and the other half are due to spontaneous genetic mutation. NF 1 and NF 2 are each related to changes in separate genes: The NF1 gene is located on chromosome 17 and NF2 has been traced to chromosome 22 (Sharp 1). These findings are important because they have led to the development of a genetic test that can reliably confirm NF in affected individuals. It is important to understand the difference between a sign and a symptom. Though signs and symptoms describe the same conditions, these two are different in many characteristics.
While signs are what a doctor sees, symptoms are what a patient experiences. A symptom can be defined as one of the characters of a disease. Meanwhile, sign is the definite indication of a specific disease. Signs are objective. Symptoms on the other hand are subjective (Signs vs Symptoms 1). Doctors diagnose the different types based on the symptoms. The first noticeable sign is the presence of brown cafe au lait spots (Washington 2). These distinctive spots don’t hurt or itch and never progress to anything more serious than spots.
They can be found anywhere on the body, though not usually on the face. They may be seen under the arms or in the groin area. Many neurofibromas can be removed and are non-cancerous. Many people who do not have NF may see a few cafe-au-lait spots. However, if a young child has more than 5 that are at least ? inch in size, other clues will be looked for that may indicate NF, including neurofibromas and Lisch nodules which are tiny, noncancerous tumors on the iris of the eye (Washington 3). Lisch nodules are of no clinical significance except that they help confirm a diagnosis of NF (Washington 3).
Neurofibromas often become evident on various parts of the body, beginning at the arms, around 10 years of age. A child may also develop freckling in the folds of the skin, armpit or groin, or on other parts of the body where the skin creases. Abnormalities of the skeleton, such as the thinning or overgrowth of the bones in the arms or lower leg, curvature of the spine (scoliosis), and other bone deformities also may be features of NF1 (Washington 3). In most cases NF1 symptoms are mild and not life threatening, leaving most patients living a normal life.
There are some instances however the disease can be dangerous. For example, neurofibromas are large growths on the outside of the body usually found on the foot and can often be embarrassing and discomforting. Another harsh effect of NF1 is learning disabilities in children, such as not being able to read, write, and comprehend. NF2 is usually not diagnosed until a child is older normally around the teenage years. It is 10 times less common than NF1. NF2 differs from person to person which is one of the most complicating things about it for researchers.
Even symptoms can differ from family member to family member. Hearing loss in the late teens and early twenties is often among the first symptoms of the disorder, and is caused by tumors growing on the auditory nerves which carry electrical impulses from the inner ear to the brain, allowing us to hear on one or both sides (GARD 3). Other symptoms of NF2 include continuous ringing in the ears, headache, facial pain or weakness, and feeling unsteady or off balance. There is a collection of clinicians and laboratory scientists working hard on focusing research of NF and the care of individuals with the disease.
The most major research center is found at the University of Washington known as the NF Center. The team uses several techniques in their studies such as Pre-clinical evaluation of new brain tumor therapies in NF1 using genetically engineered mice. These studies are designed to rapidly test the most promising candidate drugs prior to their evaluation in children with NF1. One such drug, rapamycin, is now in clinical trials for children with NF1 associated glioma (Washington 4). Another technique is used to determine the role in NF2 gene in ependymal formation.
In order to develop more targeted treatments for these tumors, Dr. David Gutmann has employed NF2 genetically engineered mice as well to define the mechanism underlying NF2 protein (merlin) regulation of spinal cord flail cell and progenitor cell growth (Washington 4). His studies have revealed new ways that merlin controls cell growth in the nervous system. The Washington lab has also came up with a unique idea to help other physicians and researchers better understand the spectrum of medical problems found in NF patients.
It is a Patient Registry where they offer each patient a 30 question questionnaire, and the information found is used to better characterize the relationships between specific problems of both types of NF, also allowing researchers to understand direct correlations between NF and problems with internal organs such as the heart, brain, and spinal cord. Each year emails are sent to patients reminding them to update their information on the registry. Tests like magnetic resonance imaging (MRI) and X-rays may be used to screen for tumors or evidence of skeletal problems.
A child’s head circumference will be measured, as kids with symptoms of NF can have a circumference that’s larger than normal for their age (Neurofibromatosis 3). Blood pressure will be monitored. Doctors also take a detailed personal history, looking for signs of learning difficulties. To diagnose NF2, doctors will check for any evidence of hearing loss. They’ll order audiometry (hearing tests) as well as imaging tests to look for tumors in the nerves of the ears, spinal cord, or brain (Neurofibromatosis 3). They’ll also determine if there’s a family history of NF2.
Genetic testing is now available for people with a family history of either NF1 or NF2. Although testing is still not 100% sensitive, recent advances have increased sensitivity to over 90%. Amniocentesis or chorionic villus sampling can sometimes determine if an unborn child has the condition (Neurofibromatosis 3). In closing, there is no cure for NF. Treatment can help control symptoms. The disease can be noticed by signs and symptoms and can be passed through pregnancy. Depending on the type of disease and how bad it is, treatment may include surgery to remove tumors, radiation therapy, and medicines.
For more information of each type of Neurofibromatosis, request an appointment, research, or treatments please visit the Washington University Neurofibromatosis Center website. References Clarker, J. 2009. Genetic and Rare Diseases. GARD: 102-111 Sharpe, John, Harsburg Roy, et al. 2001. The Effect of Pregnancy. Neurofibromatosis: 20-35. Honaker, Caprice. 2005. Symptoms and Signs. Neurofibromatosis 1 and 2: 1-25. Maylaihan, Drey. 2000. Research. Washington NF Center: Registry Listings: 1-32. Jay, Susan, Roberts, Ray. 2004. UK Patients. Neurofibromatosis: 3-20.