title: Use of the national institutes of health criteria for diagnosis of neurofibromatosis 1 in children.
abstract: OBJECTIVE
  The National Institutes of Health (NIH) Diagnostic Criteria for neurofibromatosis 1 (NF1) are very useful clinically, but some individuals who are later shown to have NF1 cannot be diagnosed in early childhood using these criteria. The aim of this study is to determine the value of the NIH Diagnostic Criteria for NF1 in early childhood, to determine the age at which diagnosis can confidently be made, and to clarify the age at onset of the cardinal clinical features used in the NIH Diagnostic Criteria.
  
  
  METHODS
  We studied 1893 NF1 patients under 21 years old from the National Neurofibromatosis Foundation International Database to determine the age at which the features included in the NIH Diagnostic Criteria appear.
  
  
  RESULTS
  Approximately 46% of sporadic NF1 cases fail to meet the NIH Diagnostic Criteria by 1 year of age. Nearly all (97%; 95% confidence interval: 94-98) NF1 patients meet the criteria for diagnosis by 8 years old, and all do so by 20 years old. The usual order of appearance of the clinical features listed as NIH criteria is café-au-lait macules, axillary freckling, Lisch nodules, and neurofibromas. Symptomatic optic glioma is usually diagnosed by 3 years old, and characteristic osseous lesions are usually apparent within the first year of life.
  
  
  CONCLUSIONS
  The diagnosis of NF1 cannot always be made in young children using the NIH Diagnostic Criteria. Modification of these criteria may be necessary for children under 8 years old.
authors.affiliation: Department of Medical Genetics, University of British Columbia, Vancouver, Canada.
authors.forename: K
authors.initials: K
authors.lastname: DeBella
authors.forename: J
authors.initials: J
authors.lastname: Szudek
authors.forename: J M
authors.initials: JM
authors.lastname: Friedman
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009316:National Institutes of Health (U.S.); D009456:Neurofibromatosis 1 / Q000175:diagnosis* / Q000235:genetics; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D014481:United States