RT-PCR and bi-directional sequencing of the variable region of the immunoglobulin heavy chain for detection of mutation from germline sequence. The mutated VH gene family is identified in positive reports (>3% sequence deviation). Mutation may not be detectable in specimens containing <10% clonal B-cells.
IgVH mutation is a significant prognostic marker in chronic lymphocytic leukemia (CLL). IgVH mutation analysis combined with FISH, ZAP-70, and beta-2 microglobulin measurement provide comprehensive prognostic assessment and may be used to determine the approach to therapy for all CLL patients.
- Peripheral blood: 5 mL in EDTA tube.
- Bone marrow: 2 mL in EDTA tube.
Use cold pack for transport, making sure cold pack is not in direct contact with specimen. Ship same day as drawn whenever possible; specimens <72 hours old preferred.