Patient with neurofibromatosis. Neurofibromatosis (NF) refers to a number of inherited conditions that are clinically and genetically distinct and carry a high risk of tumour formation, particularly in the brain. Neurofibromatosis is an autosomal dominant disorder, which means only one copy of the affected gene is needed for the disorder to develop. Therefore, if only one parent has neurofibromatosis, his or her children have a 50% chance of developing the condition as well (it is rarely the case that one person has the mutated gene twice, which would imply a 100% chance of their children developing NF).