Analysis of Isocitrate Dehydrogenase 1 Mutation and 10q23/PTEN Alterations in Turkish Glioblastoma Patients

INTRODUCTION: The object of this study is to identify the frequency isocitrate dehydrogenase 1 gene (IDH1) mutations and 10q23/PTEN locus alterations in Turkish patients with glioblastoma multiforme (GBM).
METHODS: For this purpose, DNAs obtained from paraffin-embedded archival materials belong to 54 cases diagnosed as GBM were applied direct sequencing. In addition, overall 25 cases and 10 non-neoplastic brain tissues which were used as controls were analyzed by fluorescent in situ hybridization (FISH).
RESULTS: We detected 5 heterozygous IDH1 c.395G>A mutations (9.3%) with wild-type arginine 132 replaced by histidine (R132H). Although there is no statistical significance between the age of the cases and IDH1 p.R132H mutation, the patients harboring the p.R132H mutation were younger (median age; 38) than patients without this mutation (median age; 52). The median survival time of the patients with this mutation was calculated at 7 months, while it was 5 months for the patients with no mutation; however, this finding was not statistically significant. According to our FISH results, we found a total of 16 10q23/PTEN alterations, of which 8 were hemizygous deletion (32%) and 8 were monosomy (32%).
DISCUSSION AND CONCLUSION: Understanding the prevalence of IDH1 mutations and 10q23/PTEN alterations may have importance in terms of the diagnosis, prognosis, and treatment of GBM patients.