Possible markers of monoclonality in twin leukemia
Marker . | Limitations . |
|---|---|
| Chromosome markers | Some markers common in independent leukemias |
| Marker may be secondary or late event | |
| IGH/TCR VD(N)J clonal rearrangements | Initial leukemic cell transformation may precede rearrangements |
| Rearrangements may not be stable | |
| X-linked allele expression in female pairs | Can be concordant for allele expression by chance (50%), but discordance of allele expression is strong evidence against monoclonality |
| “Oncogene”-specific sequence (eg, fusion gene) | May not be initiating or early event |
Marker . | Limitations . |
|---|---|
| Chromosome markers | Some markers common in independent leukemias |
| Marker may be secondary or late event | |
| IGH/TCR VD(N)J clonal rearrangements | Initial leukemic cell transformation may precede rearrangements |
| Rearrangements may not be stable | |
| X-linked allele expression in female pairs | Can be concordant for allele expression by chance (50%), but discordance of allele expression is strong evidence against monoclonality |
| “Oncogene”-specific sequence (eg, fusion gene) | May not be initiating or early event |