Recently age and surgical resection of the tumor mass are the accepted variables important for glioma progression but the distinction of biological properties of glial tumours is extremely important for both the selection of the appropriate treatment method and the prolongation of the survival. Researches confirmed that p53 mutations are present in 60% of the initial stage gliomas and that 70-80 % of all gliomas had loss of p53 gene function. P14ARF and mdm2 aberrations effect P53 function and especially act on the progression through higher grade gliomas. In this study, tumour tissues of 39 and 9 patients applied to Marmara University Neurosurgery Department and Haydarpasa Numune Hospital respectively between April 1999- January 2005, accepted informed consent and had glioma surgery, are used; Following DNA isolation p53 mutations are detected by SSCP, mdm2 amplifications and P14 deletions are studied with multiplex PCR technique. Among Fourtyeight cases of this study 22 patients of the total group had p53 mutations. P53 protein expression of all three histopathological groups has found to be increased in mutation positive specimens than in non-mutated specimens at a statistically significant level (p<0.05). With the survival analysis p53 mutation carriers are found to live shorter compared to non-carriers. Patients with p53 mutations are considered to have unfavourable prognosis for this grade tumours. P14 deletions and MDM2 amplifications are not specific for this group of tumours and in this study they are not found to be statistically important.

Key Words; Low grade glioma, p53 mutations, p53 pathway aberrations, survival.