IDH3A and astrocytoma (excluding glioblastoma): Gliomas are diverse group of tumors which are now classified into three major subtypes; oligodendroglioma (ODG) which are isocitrate-dehydrogenase (IDH)-Mutant (Mut) along with 1p/19q co-deletion, astrocytoma (ATC) which are IDH-Mut without 1p/19q co-deletion and GBM which are IDH wildtype (WT).