Neurofibromatosis type 2 with multiple primary brain tumors in monozygotictwins

BACKGROUND Although monozygotic twins with neurofibromatosis complicated by brain tumors rarely have been reported, none of them fulfilled the diagnos tic criteria for neurofibromatosis type 2 (NF2). METHOD We describe here the first pair of monozygotic twins with NF2, and t he result of the molecular analysis of their NF2 gene. RESULTS One of the brothers (Case 1) developed tetraparesis and cerebellar truncal ataxia at age 12. He had no skin lesions. Radiological examinations revealed, at one time or another, bilateral vestibular schwannomas, a fora men magnum meningioma, five supratentorial meningiomas, and multiple spinal cord tumors. He underwent three operations over a 10-year period to remove tumors. The patient is now 23 years old and is in college. Although asympt omatic when examined at age 12, CT scan revealed that his brother (Case 2) also had multiple brain tumors, including meningiomas, schwannomas, and mul tiple spinal tumors. Tumors were removed in eight operations over a 10-year period. The patient is now deaf and confined to a wheelchair. An identical nonsense mutation caused by a C to T transition (C169) in a CPG dinucleoti de of the NF2 gene was identified in both patients. CONCLUSION These results led us to speculate that dissimilarities with resp ect to time of appearance, distribution, and extent of symptoms and tumors between the twins were dependent on the influence of other genetic factors. (C) 1999 by Elsevier Science Inc.