Table 5. Four distinct molecular/genetic subgroups in medulloblastoma.
| WNT | SHH | Group 3 | Group 4 | |
|---|---|---|---|---|
| Frequency (%) | 10 | 30 | 25 | 35 |
| Age (years) | >3 | <3 and >16 | <16 | all |
| Male:female | 1:1 | 1:1 | 2:1 | 2:1 |
| Metastatic (%) | 5-10 | 15-20 | 45 | 35 |
| Histology | Classical | Classical; DN (50%) | Classical; LCA (35%) | Classical |
| Survival (%) | >90 | 60-80 | 50 | 75 |
| Distinct genetic aberrations | CTNNB1 | PTCH1 | MYC amplification | |
| Chromosomal abnormality | 6- (~100%) | i17q (65%); X- (80% female) |
SHH, sonic hedgehog; DN, desmoplastic/nodular; LCA, large cell/anaplasia; WNT, wingless/integrated.