Introduction to neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is a tumour predisposition syndrome with an estimated frequency of about one in 3000 people. Most symptoms of neurofibromatosis type 1 arise from local pressure exerted by nonmalignant tumours (neurofibromas), particularly in the central and peripheral nervous systems.

Neurofibromatosis type 1 has neurodevelopmental effects that can cause significant disability. Learning disorders are common (up to 50% of patients) and range from subtle to severe. The median life expectancy of people with neurofibromatosis type 1 is 8 years younger than the general population, with malignancy and vasculopathy being the most common causes of premature deathFriedman, 1998.

Neurofibromatosis type 1 arises from autosomal dominant mutations within the NF1 gene, and a diagnosis has reproductive and familial implications (see Genetic counselling). Mutations of the NF1 gene may be inherited from an affected parent (about 50% of patients) or may arise as a new dominant (sporadic) mutation.

The Children’s Tumour Foundation provides support for people with neurofibromatosis type 1 and their families.

Neurofibromatosis type 2 (NF2) is also a tumour predisposition disorder with autosomal dominant inheritance, but its genetic basis is different from neurofibromatosis type 1. It is characterised by bilateral vestibular schwannomas (acoustic neuromas) and other tumours of the central and peripheral nervous systems (including schwannomas and meningiomas). Neurofibromatosis type 2 is much rarer than neurofibromatosis type 1 (frequency about one in 30 000). For more information about neurofibromatosis type 2, see GeneReviews (National Center for Biotechnology Information [U.S. National Library of Medicine]).