HEREDITARY SPINAL NEUROFIBROMATOSIS - A RARE FORM OF NF1

We describe a family in which seven members in three generations were affected with a rare spinal neurofibromatosis. The affected adults sho wed, at the ages of 32, 37, 38, and 61, respectively, multiple spinal neurofibromas symmetrically affecting all spinal roots. Two patients w ere operated on for histopathologically proven cervical spinal neurofi bromas. All patients had cafe au lait spots, one had several freckles in the axillary area, and two had possible dermal neurofibromas, but i ris Lisch nodules were not present. Other signs of neurofibromatosis t ypes 1 and 2 were absent. A linkage study of the family suggested clos e linkage to the NF1 locus and excluded it from the NF2 locus. The DNA analysis of histopathologically verified spinal neurofibromas in two patients showed no evidence of LOH at 17q11.2. The findings in the pre sent family, together with those in a family previously described, sug gest a clinically distinct form of neurofibromatosis with extensive sp inal neurofibromas and cafe au lait macules, which may be allelic to t he NF1 gene.