Somatic Mosaicism of NF2 Gene Mutation with Constitutional NF1 Gene Mutation in Neurofibromatosis Type 2: a Case Report.

Background: Neurofibromatosis (NF) is a genetic disorder, and neurofibromatosis types 1 and 2 have different genetic and clinical features. Herein, we present the clinical and genetic aspects of a patient carrying a constitutional NF1 gene mutation and whose neurocutaneous manifestations suggested a NF type 2 (NF2).

Methods: A 55-year-old woman presented with headache and deterioration of vision. Physical examination and radiologic findings revealed multiple subcutaneous nodules and multiple intracranial and spinal masses which were suspected to be NF2.

Results: Genomic DNA sequencing using a peripheral blood sample revealed a splicing mutation in the NF1 gene. Tumor resection and biopsy revealed intracranial meningiomas and paraspinal Schwannoma compatible with NF2. PCR-direct sequencing using tumor tissue samples showed pathogenic somatic mutation of the NF2 gene.

Conclusions: We report a case of NF2 presenting with a pathogenic somatic mutation in the NF2 gene in a woman harboring a germline splicing mutation in the NF1 gene. This case emphasizes the importance of sequence analy¬sis by using tumor tissues and the need to elucidate the role of a NF1 splicing mutation.