NF1 and neurofibroma: Patients with spinal neurofibromatosis have multiple spinal neurofibromas without café-au-lait macules whereas patients with a 3-bp inframe deletion in exon 17 of the NF1 gene have café-au-lait macules without neurofibromas.[37] Our data suggests that this inverse relationship may apply to a broader subset of patients than previously recognized.