Aim: The aim of our study was to evaluate the frequency of deletions on chromosomes 1, 9, 10, 14, 18 and 22 in 75 benign and 15 atypical meningiomas and correlate them with clinical findings. Methods: Paired normal and tumour DNA samples obtained from the patients operated on, were analyzed for loss of heterozygosity (LOH), using 24 microsatellite markers and PCR techniques. Results: Statistical analysis showed that deletions on chromosomes 14 and 18 were significantly associated with WHO grade of the meningiomas (p=0.048 and p=0.03, respectively). In addition, LOH on chromosome 14 was significantly associated with tumour size (p=0.048), as the risk of developing a tumour larger than 4 cm in diameter was 6-times greater than the risk of developing tumour with diameter below 4 cm. The most frequent genetic abnormality in meningiomas is 22 LOH, which was confirmed in the present study in which high frequency of such abnormality was observed (66%). There was a clear associations between chromosome 22 status and histological subtype. LOH on chromosome 22 was more frequent in fibrous meningiomas than in the meningothelial variant (p=0.001). Besides that, there was a relationship between 22 LOH status and tumour location: the frequency of LOH in skull base meningiomas was significantly lower compared to parasagittal meningiomas (p=0.0004). Conclusions: These results indicated that allelic loss on chromosomes 9, 10, 14, 18 and 22 may be associated with meningioma pathogenesis and progression.

meningioma, loss of heterozygosity (LOH), retention of heterozygosity (ROH), meningioma pathogenesis, molecular alternations in meningiomas