Bidirectional sequencing revealed a heterozygous single nucleotide duplication in exon 2 of CDKN2A (NG_007485.1:g.28291dup) in DNA from a patient with five nerve sheath tumors (two were considered hybrid tumors with high schwann cell content but some neurofibroma features). This evidence concerns the gene CDKN2A and plexiform neurofibroma.