Disease Overview

Neurofibromatosis type 1 (NF1) is a relatively common genetic condition that is estimated to occur in 1 in 3000 live births worldwide and causes tumors to grow along nerves1-3
It is an autosomal dominant condition driven by pathogenic variants of the NF1 gene. Pathogenic variants can either be inherited or can occur spontaneously.2
characterized by increased risk of developing noncancerous (benign) and cancerous (malignant) tumors, as well as various other physical and neurological manifestations2

Neurofibromatosis is not a single medical disorder1

Neurofibromatosis refers to 3 Different conditions involving the development of tumors that may affect

Brain1
Spinal Cord1
Nerves

NF1 manifests as a range of symptoms (Temp Heading)

50% Of people with NF1 have plexiform neurofibromas, but most are internal and not suspected clinically3

Life expectancy reduced by ~20 years4

NF1 manifests as a range of symptoms

Patients with NF1 experience a range of symptoms with varying degrees of severity, which can change over time.2,3 Common symptoms include cutaneous neurofibromas, plexiform neurofibromas (PN), café-au-lait macules, axillary or inguinal freckling, skeletal defects, optic nerve or central nervous system gliomas, as well as neurocognitive dysfunction.1

NF1 Symptoms

Adapted from references: 1-3

NF1-PN

  • Approximately 30-50% patients with NF1 have PN, a tumour of peripheral nerves arising from a bundle of fascicles or a larger nerve plexus.5 PN may remain asymptomatic or can invade surrounding muscle and bone, causing substantial pain and disfigurement.1
  • PN are considered congenital and may grow most rapidly in the first decade of life.5 They commonly occur in the head and neck region, trunk or extremities, but can affect nerves between the spinal root and the distal periphery.4,6

PN are at risk of malignant transformation1

  • PN are associated with an increased risk for malignant transformation to malignant peripheral nerve sheath tumours (MPNSTs).1 Patients with NF1 have a cumulative 8–16% lifetime risk of developing MPNST, which usually occurs between the ages of 20 and 35 years.1

NF1-PN may represent a major source of morbidity and have the potential to cause:3,6

Disfigurement
Motor dysfunction
Pain
Airway compromise
Bladder / bowel dysfunction
Visual impairment

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References:

  • Bergqvist C et al. Neurofibromatosis 1 French national guidelines based on an extensive literature review since 1966. Orphanet J Rare Dis. 2020;15(1):37.
  • Yap YS et al. The NF1 gene revisited – from bench to bedside. Oncotarget. 2014;5(15):5873–5892.
  • NHS. Neurofibromatosis type 1: Symptoms. Available at: https://www.nhs.uk/conditions/neurofibromatosis-type-1/symptoms/ Last accessed: January 2024.
  • Blakeley JO and Plotkin SR. Therapeutic advances for the tumors associated with neurofibromatosis type 1, type 2, and schwannomatosis. Neuro Oncol. 2016;18(5):624–638.
  • Anderson JL et al. Neurofibromatosis type 1. Handb Clin Neurol. 2015;132:75–86.
  • Gross AM et al. Association of plexiform neurofibroma volume changes and development of clinical morbidities in neurofibromatosis 1. Neuro Oncol. 2018;20(12):1643–1651.