[A novel indel NF1 mutation identified in a patient with neurofibromatosis type 1]

To identify the genetic etiology in a Chinese patient with neurofibromatosis type 1 (NF-1).

All coding exons and the flanking sequences of neurofibromin 1 (NF1) gene from the patient were captured, individually barcoded and subjected to HiSeq2000 high-throughput sequencing. Suspected mutation was validated in the nuclear family members with Sanger sequencing.

A novel indel mutation, c.789_790delAGinsT, was identified in the exon 8 of the NF1 gene in the patient but not in her asymptomatic parents. The mutation was predicted to have caused shifting of the reading frame and a premature downstream stop codon (p.K263Nfs*18). Two known polymorphisms, c.888+108 C>T (rs2953000) and c.888+118 G>T (rs2952999), was detected in the flanking of the indel mutation in the patient and her father. Sequencing chromatogram for the family indicates that above changes are located on the same chromosome.

The c.789_790delAGinsT, as a de novo mutation occurring on the paternally derived chromosome, is most likely to be causative for the disease. Compared with Sanger sequencing, targeted next-generation sequencing is more efficient and can dramatically reduce the cost for the genetic testing of NF-1.