Loss of merlin expression in sporadic meningiomas, ependymomas and schwannomas.

Neurofibromatosis 2 (NF2) is an inherited disorder in which affected individuals develop schwannomas and meningiomas. NF2 is mapped to chromosome 22q in a region where frequent loss of heterozygosity also occurs in sporadic meningiomas, ependymomas, and schwannomas. Using NF2 protein (merlin or schwannomin)-specific antibodies, 11 of 14 sporadic schwannomas, three of eight sporadic ependymomas, and 16 of 19 sporadic meningiomas demonstrated significantly reduced or absent merlin expression, suggesting that NF2 may be involved in the pathogenesis of these sporadic tumors.