P04.12 Characteristics of IDH-mutant gliomas with non-canonical IDH mutations

Abstract BACKGROUND About 10% of IDH-mutant gliomas harbor non-canonical IDH mutations (non-R132H IDH1 and IDH2 mutations). The aim of the present study was to analyze the characteristics of these gliomas in comparison to those of IDH1 R132H mutant gliomas. MATERIAL AND METHODS We retrospectively analyzed the characteristics of a multicentric series of 161 gliomas with non-canonical IDH mutations and compared them to those of consecutive series of 109 IDH1 R132H mutant gliomas. Medical, radiological and pathological were reviewed. RESULTS Median age at diagnosis was 35 years in gliomas with a non-canonical IDH1 mutation, 42 years in those with an IDH2 mutation and 44 years in those with an IDH1R132H mutation. A familial history of cancer was more frequent in gliomas with a non-canonical IDH mutation than in those with an IDH1 R132H mutation (22,3% vs 5,5%, p