Neurofibromatosis Type 1 (NF1)
NF1 is caused by a mutation in the NF1 gene. This faulty gene leads to uncontrolled growth (tumors) developing in the nervous system. In about half of the cases, the faulty gene is inherited from a parent. Only one parent needs to have the faulty gene for their child to be at risk. If either parent has the faulty gene, there is a 50% chance that each child will develop NF1. In other cases, the mutation occurs spontaneously, with no family history of NF1. The reason for this spontaneous mutation is unclear. Children who develop NF1 spontaneously can still pass the condition to their offspring.
Neurofibromatosis Type 2 (NF2)
NF2 is caused by a mutation in the NF2 gene, leading to the development of tumors in the nervous system. In about half of the cases, the faulty gene is inherited from a parent, with a 50% chance of passing it to each child. The mutation can also occur spontaneously, with no clear reason. Mosaic NF2, a milder form of the disease, affects about one-third of people with NF2 and is often restricted to a certain area or side of the body. Individuals with mosaic NF2 have a lower risk of passing the condition to their children.
Schwannomatosis
The exact cause of schwannomatosis is not well understood. Some cases are linked to mutations in the SMARCB1 or LZTR1 genes. Unlike NF1 and NF2, schwannomatosis does not follow a clear inheritance pattern and often occurs sporadically.
