LOSS OF HETEROZYGOSITY OF CHROMOSOME 14Q IN LOW-GRADE AND HIGH-GRADE MENINGIOMAS

Abnormalities of chromosome 22q have been well studied as a major mole cular genetic event in meningiomas. Chromosome 14q loss has also been shown to be a common phenomenon, However, only a few studies have repo rted molecular genetic changes of this chromosome in meningioma. In th is study, we examined 41 sporadic meningiomas of different histologica l subtypes and grades with 15 polymorphic microsatellite markers cover ing a wide region on chromosome 14q. Overall, 37% (15 of 41) of cases showed loss of heterozygosity for one or more allelic markers. Thirty percent (10 of 33) of benign tumors showed allelic losses, whereas 62. 5% (5 of 8) of high-grade meningiomas showed loss of heterozygosity. T here were altogether eight cases of partial deletions and seven cases of probable monosomy of 14q. Allelic losses of 14q were also commonly seen in recurrent tumors (3 of 3, 100%), parasagittal tumors (4 of 7, 57%), and tumors with transitional subtype (7 of 14, 50%). Among the t umors with allelic losses of 14q, all except one concurrently showed l oss of heterozygosity for markers on 22q by our previous study. Of the eight cases with partial deletions, one showed losses on 14q11.1-31, two showed deletions on 14q24.3-31, three showed losses at 14q32.1-32. 2, and the remaining two showed deletions at 14q24.3-32.2. We therefor e defined two cluster regions of deletion on chromosome 14q: 14q24.3-3 1 and 14q32.1-32.2. Our studies suggested that more than one tumor sup pressor gene(s) residing on distinct regions of chromosome 14q are imp ortant in the development and atypical or anaplastic changes in mening iomas. HUM PATHOL 28:779-785. Copyright (C) 1997 by W.B. Saunders Comp any.