NEUROFIBROMATOSIS TYPE 1 (NF1) What is neurofibromatosis type 1
(NF1)? NF1 is a disorder characterized by the growth of
noncancerous tumors called neurofibromas. They usually form on
or just underneath the skin, as well as in the brain and
peripheral nervous system. But they can also develop in other
parts of the body, such as the eye. The disorder is caused by a
mutation in a gene on chromosome 17. The gene codes for a
protein called neurofibromin. This protein regulates the
activity of another protein called ras, which promotes cell
division. When the NF1 gene is mutated, it usually leads to a
shortened version of the neurofibromin protein that cannot bind
to ras or regulate its activity. As a result, the ras protein is
more active. Cells are told to begin dividing and never told
when to stop, causing the formation of tumors. How do people get
NF1? In about half of all cases, a person inherits the mutated
gene from a parent. The disorder is inherited in an autosomal
dominant pattern, which means that only o