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New and Improved: The way to talk about NF

By May 9, 2023May 24th, 2024Press Release

You may have heard that some exciting discoveries have changed how we talk about NF. Part of the mission of the Children’s Tumor Foundation is to expand knowledge. With new knowledge comes a better understanding and an improved way of talking about NF.

Let’s get to the point – a new definition of NF: 

NF refers to a group of genetic conditions that cause tumors to grow on nerves throughout the body. NF includes neurofibromatosis type 1 (NF1) and all types of schwannomatosis (SWN), including NF2-related schwannomatosis (NF2-SWN), formerly known as neurofibromatosis type 2. 

Let’s break that down: 

  • NF collectively refers to NF1, SWN, and NF2-SWN 
    • The abbreviation “NF” is not being used solely as a short form of the word neurofibromatosis, but refers to both neurofibromatosis and schwannomatosis collectively
  • NF1 refers to neurofibromatosis type 1
    • NF does not refer to just NF1
  • Since 2022, SWN refers to schwannomatosis, which is an umbrella term to refer to many sub-types of schwannomatosis (read more below) **
    • Types of schwannomatosis are named according to the genetic information used to diagnose the condition, with gene names in italics:
      • NF2-related schwannomatosis
      • SMARCB1-related schwannomatosis
      • LZTR1-related schwannomatosis
      • 22q-related schwannomatosis
      • Schwannomatosis NOS or NEC (used when there is no genetic information)
  • NF2-SWN refers to NF2-related schwannomatosis ** 
    • The term “neurofibromatosis type 2” is no longer used

Let’s get to the nitty-gritty: 

  • NF is caused by a pathogenic (disease-causing) variant or a “change in a gene”
    • The word “mutation” is no longer used
  • NF is a genetic condition or a disease 
    • The word “disorder” is being phased out
  • Gene names are in italics, but the diagnosis is not
    • For example: A change in the NF1 gene causes a diagnosis of NF1

Let’s talk numbers – the birth incidence of NF:

Thanks to advancements in NF research, we now know NF is more common than previously reported.

  • Some type of NF occurs in approximately 1 in 2,000 births
  • NF1 occurs approximately in 1 in 2,500 births
  • Some type of SWN occurs in approximately 1 in 20,000 births
    • NF2-related schwannomatosis occurs in approximately 1 of 25,000 births
    • SWN (excluding NF2-SWN) occurs in approximately 1 in 70,000 births.
  • We are currently reporting that approximately 4 million people worldwide are affected by some form of NF.

Let’s stick with NF:

CTF will no longer compare the incidence of other conditions with that of NF. In the past, our talking points included “NF is more common than …” and named several other conditions thought to be more well-known than NF. That information may no longer be accurate. More important, thanks to the incredible awareness efforts of the NF community over the past 40 years, that message is no longer needed.

We hope you are as excited about these changes as we are! Change can be difficult, but over time and with practice, this new way of talking about NF will feel natural. What’s most important…

Let’s talk about NF!

To view this information as a downloadable pdf, CLICK HERE

To find updated brochures and fact sheets about NF on our Resource Library, CLICK HERE

Questions? Please see notes and references below. 




** There are many sub-types of SWN.  We name them using a system developed by the American College of Medical Genetics and Genomics. In this system, we name each sub-type based on the gene with the genetic variant.  So, for example, if a person has multiple schwannomas due to a pathogenic variant in the NF2 gene, we call that “NF2-related schwannomatosis.” (Please remember that genes are shown in italics).


Diagnostic Criteria and Terminology Update  – Read more about the 2022 SWN and NF2-SWN diagnostic criteria update HERE.

Plotkin, S. R., Messiaen, L., Legius, E., Pancza, P., Avery, R. A., Blakeley, J. O., Babovic-Vuksanovic, D., Ferner, R., Fisher, M. J., Friedman, J. M., Giovannini, M., Gutmann, D. H., Hanemann, C. O., Kalamarides, M., Kehrer-Sawatzki, H., Korf, B. R., Mautner, V., MacCollin, M., Papi, L., . . . Evans, D. G. (2022). Updated diagnostic criteria and nomenclature for neurofibromatosis type 2 and schwannomatosis: An international consensus recommendation. Genetics in Medicine, 24(9), 1967-1977.

Legius, E., Messiaen, L., Wolkenstein, P., Pancza, P., Avery, R. A., Berman, Y., Blakeley, J., Cunha, K. S., Ferner, R., Fisher, M. J., Friedman, J. M., Gutmann, D. H., Korf, B. R., Mautner, V., Peltonen, S., Rauen, K. A., Riccardi, V., Schorry, E., Stevenson, D. A., . . . Plotkin, S. R. (2021). Revised diagnostic criteria for neurofibromatosis type 1 and Legius syndrome: An international consensus recommendation. Genetics in Medicine, 23(8), 1506-1513.


Birth Incidence Numbers

Evans DG, Bowers NL, Tobi S, Hartley C, Wallace AJ, King AT, Lloyd SKW, Rutherford SA, Hammerbeck-Ward C, Pathmanaban ON, Freeman SR, Ealing J, Kellett M, Laitt R, Thomas O, Halliday D, Ferner R, Taylor A, Duff C, Harkness EF, Smith MJ. Schwannomatosis: a genetic and epidemiological study. J Neurol Neurosurg Psychiatry. 2018 Nov;89(11):1215-1219. doi: 10.1136/jnnp-2018-318538. Epub 2018 Jun 16. PMID: 29909380.

Kallionpää RA, Uusitalo E, Leppävirta J, Pöyhönen M, Peltonen S, Peltonen J. Prevalence of neurofibromatosis type 1 in the Finnish population. Genet Med. 2018 Sep;20(9):1082-1086. doi: 10.1038/gim.2017.215. Epub 2017 Dec 7. PMID: 29215653.

Evans DG, Howard E, Giblin C, Clancy T, Spencer H, Huson SM, Lalloo F. Birth incidence and prevalence of tumor-prone syndromes: estimates from a UK family genetic register service. Am J Med Genet A. 2010 Feb;152A(2):327-32. doi: 10.1002/ajmg.a.33139. PMID: 20082463.


Other terminology updates

Richards S, Aziz N, Bale S, Bick D, Das S, Gastier-Foster J, Grody WW, Hegde M, Lyon E, Spector E, Voelkerding K, Rehm HL; ACMG Laboratory Quality Assurance Committee. Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Genet Med. 2015 May;17(5):405-24. doi: 10.1038/gim.2015.30. Epub 2015 Mar 5. PMID: 25741868; PMCID: PMC4544753.