Spinal neurofibromatosis associated with classical neurofibromatosis type 1: genetic characterisation of an atypical case.

Spinal tumours are observed in about 40% of neurofibromatosis type 1 (NF1) patients and occur within two subgroups: (1) NF1 patients carrying classical diagnostic criteria and only one or few spinal tumours and (2) patients with few NF1 stigmata but multiple bilateral spinal tumours, an entity called spinal neurofibromatosis. We report a young patient whose classical NF1 stigmata and numerous spinal neurofibromas matched both groups. He carried a single base deletion, c.389delA in exon 4a, which creates a premature termination at codon 164. This case illustrates the possibility of variant phenotypes and a novel NF1 mutation associated with spinal neurofibromatosis.