Use of the National Institutes of Health Criteria for diagnosis of neurofibromatosis 1 in children

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 usin g these criteria. The aim of this study is to determine the value of the NI H Diagnostic Criteria for NF1 in early childhood, to determine the age at w hich 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 Diagn ostic 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 featu res listed as NIH criteria is cafe-au-lait macules, axillary freckling, Lis ch nodules, and neurofibromas. Symptomatic optic glioma is usually diagnose d by 3 years old, and characteristic osseous lesions are usually apparent w ithin the first year of life. Conclusion. The diagnosis of NF1 cannot always be made in young children us ing the NIH Diagnostic Criteria. Modification of these criteria may be nece ssary for children under 8 years old.