About NF

The neurofibromatoses are genetic disorders of the nervous system that primarily affect the development and growth of neural (nerve) cell tissues. These disorders cause tumors to grow on nerves and produce other abnormalities such as skin changes and bone deformities. 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.

Scientists have classified the disorders as neurofibromatosis type 1 (NF1) and neurofibromatosis type 2 (NF2). Both are conditions with autosomal dominant inheritance and were previously thought to be variants of the same disorder, but we now know them to be separate diseases due to mutations on chromosomes 17 and 22 respectively. Nonetheless, both appear to code for tumour suppressor genes and have some overlap in symptoms. The two are rarely clinically confused but the historical links between the two disorders have resulted in close ties between researchers working on NF1 and NF2.

NF1 is the more common type of the neurofibromatoses. In diagnosing NF1, a physician looks for changes in skin appearance, tumors, or bone abnormalities, and/or a parent, sibling, or child with NF1. Symptoms of NF1, 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.

NF2 is less common. NF2 is characterized by bilateral (occurring on both sides of the body) tumors on the eighth cranial nerve. The tumors cause pressure damage to neighboring nerves. To determine whether an individual has NF2, a physician looks for bilateral eighth nerve tumors and similar signs and symptoms in a parent, sibling, or child. Affected individuals may notice hearing loss as early as the teen years. Other early symptoms may include tinnitus (ringing noise in the ear) and poor balance. Headache, facial pain, or facial numbness, caused by pressure from the tumors, may also occur.

For futher information see:
NF1 Gene Test Review



NCBI GeneReviews: NF1

NCBI GeneReviews: NF2

a place of mind, The University of British Columbia

Friedman Lab
Box 153, 4500 Oak Street
Vancouver, BC, V6H 3N1