What
is NF1?
NF1
is the more common type of the neurofibromatoses, occurring in about
1 in 4,000 individuals in the United States. Although many affected
persons inherit the disorder, between 30 and 50 percent of new cases
arise spontaneously through mutation (change) in an individual's
genes. Once this change has taken place, the mutant gene can be
passed on to succeeding generations. Previously, NF1 was known as
peripheral neurofibromatosis (or von Recklinghausen's neurofibromatosis)
because some of the symptoms--skin spots and tumors--seemed to be
limited to the outer nerves, or peripheral nervous system, of the
affected person. This name is no longer technically accurate because
central nervous system tumors are now known to occur in NF1. What
are the signs and symptoms of NF1? In diagnosing NF1, a physician
looks for two or more of the following:
- five
or more light brown skin spots (cafe-au-lait macules) measuring
more than 5 millimeters in diameter in patients under the age
of puberty or more than 15 millimeters across in adults and children
over the age of puberty;
- two
or more neurofibromas (tumors that grow on a nerve or nerve tissue,
under the skin) or one plexiform neurofibroma (involving many
nerves);
- freckling
in the armpit or groin areas;
- benign
growths on the iris of the eye (known as Lisch nodules or iris
hamartomas);
- a
tumor on the optic nerve (optic glioma);
- severe
scoliosis (curvature of the spine);
- enlargement
or deformation of certain bones other than the spine;
- and
a parent, sibling, or child with NF1
When
do symptoms appear?
Symptoms,
particularly those on the skin, are often evident at birth or during
infancy, and almost always by the time a child is about 10 years
old. Neurofibromas become evident at around 10 to 15 years of age.
In most cases, symptoms are mild and patients live normal and productive
lives. In some cases, however, NF1 can be severely debilitating.
Symptoms and severity of the disorder may vary among members of
affected families.
How
is NF1 treated?
Treatments
are presently aimed at controlling symptoms. Surgery can help some
bone malformations. For scoliosis, bone surgery may be combined
with back braces. Surgery can also remove painful or disfiguring
tumors; however, there is a chance that the tumors may grow back
and in greater numbers. In the rare instances when tumors become
malignant (3 to 5 percent of all cases), treatment may include surgery,
radiation, or chemotherapy.
