Lisch nodule risk factors

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Swathi Venkatesan, M.B.B.S.[2]

Lisch Nodule Risk Factors

The biggest risk factor for neurofibromatosis is a family history of the disorder. ^[1]
- NF1 and NF2 are both autosomal dominant disorders, which means that any child of a parent with the disorder has a 50 percent chance of inheriting the genetic mutation.
- About half of people with NF1 and NF2 inherited the disease from the affected parent.
People with NF1 and NF2 that don't have affected relatives likely have a new gene mutation.
Neurofibromatosis is caused by genetic defects (mutations) that either are passed on by a parent or occur spontaneously at conception.
- The NF1 gene is located on chromosome 17. This gene produces a protein called neurofibromin that helps regulate cell growth. The mutated gene causes a loss of neurofibromin, which allows cells to grow uncontrolled.
- The NF2 gene is located on chromosome 22, and produces a protein called merlin (also called schwannomin), which suppresses tumors. The mutated gene causes a loss of merlin, leading to uncontrolled cell growth.
- Two genes are known to cause schwannomatosis. Mutations of the genes SMARCB1 and LZTR1, which suppress tumors, are associated with this type of neurofibromatosis.