%0 Journal Article %T Comprehensive genetic and epigenetic analysis of sporadic meningioma for macro-mutations on 22q and micro-mutations within the NF2 locus %A Caisa M Hansson %A Patrick G Buckley %A Giedre Grigelioniene %A Arkadiusz Piotrowski %A Anders R Hellstr£żm %A Kiran Mantripragada %A Caroline Jarbo %A Tiit Mathiesen %A Jan P Dumanski %J BMC Genomics %D 2007 %I BioMed Central %R 10.1186/1471-2164-8-16 %X Monosomy 22 was the predominant finding, detected in 47% of meningiomas. Thirteen percent of the tumors contained interstitial/terminal deletions and gains, present singly or in combinations. We defined at least two minimal overlapping regions outside the NF2 locus that are small enough (~550 kb and ~250 kb) to allow analysis of a limited number of candidate genes. Bialleinactivationo the NF2 gne was detected in 36% of meningiomas. Among the monosomy 22 cases, no additional NF2 mutations could be identified in 35% (17 out of 49) of tumors. Furthermore, the majority of tumors (9 out of 12) with interstitial/terminal deletions did not have any detectable NF2 mutations. Methylation within the NF2 promoter region was only identified at a single CpG site in one tumor sample.We confirmed previous findings of pronounced differences in mutation frequency between different histopathological subtypes. There is a higher frequency of biallelic NF2 inactivation in fibroblastic (52%) compared to meningothelial (18%) tumors. The presence of macro-mutations on 22q also shows marked differences between fibroblastic (86%) and meningothelial (39%) subtypes. Thus, inactivation of NF2, often combined with the presence of macro-mutation on 22q, is likely not as important for the development of the meningothelial subtype, as opposed to the fibroblastic form. Analysis of 40 CpG sites distributed within 750 bp of the promoter region suggests that NF2 promoter methylation does not play a major role in meningioma development.Meningiomas are the most frequently occurring intracranial tumors. Clinically treated meningiomas comprise approximately 13¨C26% of all primary brain tumors [1]. Epidemiological studies indicate that ~90% of all meningiomas are asymptomatic [2]. The majority are benign, slowly growing, solitary and sporadic tumors, but atypical or malignant meningioma constitutes approximately 10% of all cases. Meningiomas are thought to be derived from the arachnoid cap cells of the lepto %U http://www.biomedcentral.com/1471-2164/8/16