Diffuse glioma - Rare homozygous IDH point mutation, is it an oncogenetic mechanism?

Isocitrate dehydrogenase (IDH1/IDH2) mutations in gliomas of WHO grade II/III and secondary glioblastoma are almost always heterozygous missense mutations. Here, we report an extremely rare case of homozygous IDH1R132H mutation in a recurrent WHO grade III anaplastic astrocytoma. The authors here also review the relevant literature for the possible metabolic impact of homozygous IDH1/2 mutations in the gliomagenesis.