Prevalence of neurofibromatosis 1 in German children at elementary school enrollment

Objective: To determine the prevalence of neurofibromatosis 1 (NF1) among 6-year-old children in Germany. Setting and Patients: A total of 152819 children aged 6 years in 6 German states were screened for NF1 during routine medical examinations at elementary school enrollment in cooperation with local health departments in 2000 and 2001. Main Outcome Measure: The prevalence of NF1 among 6-year-old German children was estimated to be 1:2996 (95% confidence interval, 1:2260 to 1:3984). Results: Fifty-one NF1 cases were identified and confirmed by evaluation by appropriate medical specialists. Seven other children were found to have multiple cafe an lait spots without other apparent features of NF1. A minimum estimate of the crude prevalence was 3-0 per 10000 (95% confidence interval, 2.3-4.0 per 10000 population). The incidence of NF1 in this population was probably in the range of 30 to 38 cases per 100000 live births. Conclusion: Our study obtained a nearly unbiased birth incidence of NF1 of approximately 1 in 2600 to 1 in 3000 and demonstrates that NF1 can be diagnosed by age 6 years in most cases by routine physical examination with special attention to the disease-associated skin stigmata.