Neurofibromatosis

QUESTION: What can you tell me about neurofibromatosis?
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ANSWER: Neurofibromatosis is a genetically-linked disorder involving tumor
formations around various nerves. The disease can have additional widespread
effects on many of the body's systems. Two distinct forms of the disease
exist. The first type, NF-1, affects about one in 4,000 people and is
characterized by tumors along peripheral nerves and cafe-au-lait spots, which
resemble large freckles, that can appear anywhere on the body. The second
type, NF-2, is ten times less common and involves additional tumors of the
nervous system, as well as a possible loss of hearing.
Other signs of the disease, occurring in both types, include small, soft,
purplish tumors, called cutaneous neurofibromas, which can appear anywhere on
the body. Plexiform neurofibromas, causing a thickening of a large nerve
trunk, develop in some patients as well. In serious cases, these can cause
overgrowth and deformity of nearby bones. Small growths on the iris, called
Lisch nodules, freckling in skin folds such as the groin, and severe learning
disabilities are other symptoms specific to NF-1. Thus, as anyone can see,
the disease in either form can be quite disfiguring.
Exact factors leading to neurofibromatosis are still unknown, but recent
research indicates that the gene for NF-1 is located on chromosome 17 and the
gene for NF-2 is located on chromosome 22. The specific genes responsible for
the disease remain undetermined. Since afflicted women sometimes show their
first signs of the disease during pregnancy, it is further believed that
hormonal stimulation may be responsible for the growth of the neurofibromas.
However, the specific hormones have not been identified.
As yet, there is no primary treatment for the disease, so management is
aimed at early detection of treatable symptoms. Afflicted people should
receive regular physical and neurological exams and special attention should
be given to monitoring significant changes in the size or number of
neurofibromas. With NF-2 patients, acoustic nerve function must be monitored
so attempts to preserve hearing can be made. In both cases, however, genetic
counseling is of vital importance since there is a 50% chance of transmitting
the disease to offspring.
Though much about the disease is still a puzzle, promising efforts are
being made to identify the gene or genes that carry the disease. Once they
are discovered, a means for treating the disease may not be far behind.