Evaluation of Molecular and Clinical Findings in Children With Neurofibromatosis Type 1: Identification of 15 Novel Variants.

BACKGROUND

Neurofibromatosis type 1 (NF1) is the most common neurocutaneous disease and is caused by mutations in the NF1 gene. The most common clinical features of NF1 are pigmentary abnormalities such as café-au-lait spots and inguinal or axillary freckling, cutaneous and plexiform neurofibromas, hamartomas of the iris, optic gliomas, and bone lesions. The aim of this retrospective study was to define the clinical and molecular characteristics of a pediatric sample of NF1, as well as the mutational spectrum and genotype-phenotype correlation.

METHODS

The study included 40 children with clinically suspected NF1. The patients were screened for NF1 mutations by DNA-based sequencing. In addition, all the patients were studied by multiplex ligation-dependent probe amplification (MLPA) to identify any duplications or deletions in NF1. The demographic, clinical, and genetic features of the children were characterized.

RESULTS

A total of 40 children with NF1 were included. Of those, 28 were female and 12 were male. The mean age was 8.91 years. An NF1 variant was discovered in 28 of 40 patients (70%). Among these mutations, intronic mutations were the most frequently detected mutations; 15 of these variants had not been previously reported. Only one patient had a whole NF1 gene deletion.

CONCLUSIONS

This study expands the spectrum of mutations in the NF1 gene. This study also showed that genetic screening using both next-generation sequencing and MLPA had a positive effect on diagnosis and genetic counseling in patients with suspected NF1.