Sequences of IDH1 mutations. (A-E) The 5 types of IDH1 mutation. The arrow indicates the mutated nucleotide. (F) The percentages of each type of mutation. R132C comprises 37% of all types of IDH1 mutation. Only 1 of 27 IDH1-mutated patients (3.7%) has R132L. (G) The sequential study of IDH1 mutation in patient 9. The arrow points to R132H mutation in the patient.