Type 1 neurofibromatosis

Last reviewed: 2 Jun 2022
Last updated: 07 Jun 2022

Summary

Definition

History and exam

Key diagnostic factors

  • family history of NF1
  • pain, any location
  • neurological deficits: gross motor delay, general incoordination, school performance problems
  • compromised vision
  • compromised social interactions
  • skin: café au lait spots, axillary freckling, cutaneous juvenile xanthogranulomas, neurofibromas
  • head and neck: unilateral diffuse plexiform neurofibroma divisions of the trigeminal nerve
  • ophthalmological: visual compromise, optic disc pallor, iris Lisch nodules
  • central nervous system: signs of hydrocephalus, brain tumours, and/or cerebellar abnormalities
  • peripheral nervous system: palpable mass about neck, brachial plexuses, groin, Hunter's canal, or the popliteal fossae
  • skeletal: tibial dysplasia or pseudarthrosis, sphenoid wing dysplasia, pectus excavatum or carinatum, genu valgum or varum, ankle valgus, pes planus
  • gastrointestinal: severe constipation, obstipation, abdominal pain, gastrointestinal bleeding
  • vascular: neurological problems, abdominal pain (and/or haemorrhage)
  • autism spectrum disorder
  • vascular: hypertension
More key diagnostic factors

Risk factors

  • parent with NF1
  • severe crush trauma
More risk factors

Diagnostic investigations

1st investigations to order

  • MRI and/or CT scans
  • PET scan
  • biopsy
  • genetic testing to confirm NF1 mutation
More 1st investigations to order

Treatment algorithm

ACUTE

phaeochromocytoma

malignant peripheral nerve sheath tumour

ONGOING

neurofibromas: non-cutaneous

cutaneous

headache

nervous system

eye

oral

skeletal

vascular

gastrointestinal

haematopoietic

psychological

pregnancy-related

Contributors

Authors

D. Gareth Evans, MD, FRCP

Professor of Medical Genetics and Cancer Epidemiology

Genomic Medicine

School of Medicine

University of Manchester

Manchester

UK

Disclosures

DGE is an author of several studies referenced in this topic. He receives consultancies from Astrazeneca, Springworks, and Recursion. These may impact on recommendations for MEKi treatment.

Acknowledgements

Professor D. Gareth Evans would like to gratefully acknowledge Dr Vincent M. Riccardi, a previous contributor to this topic.

Disclosures

VMR is an author of several studies referenced in this topic.

Peer reviewers

Bruce R. Korf, MD, PhD

Professor

Department of Genetics

University of Alabama at Birmingham

Birmingham

AL

Disclosures

BRK declares that he has no competing interests.

Patrick Morrison, MD

Consultant in Clinical Genetics

Department of Medical Genetics

Belfast HSC Trust

Belfast

UK

Disclosures

PM declares that he has no competing interests.

Edward S. Tobias, BSc (Hons), MBChB, MRCP (UK), PhD

Clinical Senior Lecturer and Honorary Consultant in Medical Genetics

Institute of Medical Genetics

Yorkhill Hospital

University of Glasgow

Scotland

UK

Disclosures

EST declares that he has no competing interests.

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  • Differentials

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  • Guidelines

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