NF1

The NF1 gene provides instructions for making a protein called neurofibromin. This protein is produced in many types of cells, including nerve cells and specialized cells called oligodendrocytes and Schwann cells that surround nerves. These specialized cells form myelin sheaths, which are the fatty coverings that insulate and protect certain nerve cells.

Neurofibromin acts as a tumor suppressor protein. Tumor suppressors normally prevent cells from growing and dividing too rapidly or in an uncontrolled way. This protein appears to prevent cell overgrowth by turning off another protein (called ras) that stimulates cell growth and division. Other potential functions for neurofibromin are under investigation.

neurofibromatosis type 1 - caused by mutations in the NF1 gene

More than 1,000 NF1 mutations that cause neurofibromatosis type 1 have been identified. Most of these mutations are unique to a particular family. Many NF1 mutations result in the production of an extremely short version of neurofibromin. This shortened protein cannot perform its normal job of inhibiting cell division. When mutations occur in both copies of the NF1 gene in Schwann cells, the resulting loss of neurofibromin allows noncancerous tumors called neurofibromas to form. Research indicates that the formation of neurofibromas requires the interaction of Schwann cells with other cells, including mast cells. Mast cells are normally involved in wound healing and tissue repair.

cancers - associated with the NF1 gene

In rare cases, inactivation of one copy of the NF1 gene in each cell increases the risk of developing juvenile myelomonocytic leukemia (JMML). Juvenile myelomonocytic leukemia is cancer of blood-forming tissue that usually occurs in children younger than 2. This condition causes the bone marrow to make an excessive number of immature white blood cells that cannot carry out their normal infection-fighting functions. These abnormal cells can build up in the blood and bone marrow, leaving less room for healthy white blood cells, red blood cells, and platelets. Children affected by this disorder may experience fatigue, fever, and easy bleeding or bruising.