Association between mutations and brain glioma grade.

Isocitrate dehydrogenase 1/2 (/2 mutations are frequently detected in glioma. The aim of the present study was to investigate the association between /2 mutations and glioma grades. The current study was retrospective and used samples from 206 patients with brain glioma and 9 patients with spinal cord glioma as a control. Patients were diagnosed and graded according to the World Health Organization classification of tumors of the central nervous system. The association of patient age with glioma grade was evaluated, and /2 mutations were also examined and analyzed in different grades. On average, brain glioma grade tended to increase with increasing patient age; patients with grade IV (primary) gliomas had a significantly higher mean age than those with grades I and II (P<0.05), and patients with grade II glioma had a significantly lower mean age than those with grade III (P<0.05). The majority of brain gliomas with mutations in /2 in grade II, II-III and III occurred in adults, rather than adolescents. /2 mutations occurred most frequently in grade II, II-III and III gliomas, and these mutation frequencies differed significantly between brain glioma grades (P<0.001). In summary, mutations in /2 were associated with grade II, II-III and III brain gliomas, and possibly with the progression of brain glioma from grade II to grade III.