IgVH Somatic Hypermutation

Message

*Collect specimen Monday through Friday only before 1500 EST. Do not collect the day before a holiday.

Test Code

LAB00108

Alias/See Also

LAB00108
LabCorp TC: 113753
IgVH Gene Mutation
Immunoglobulin Heavy Chain Variable Region Somatic Hypermutation Analysis

CPT Codes
81263

Preferred Specimen

1.0 mL Lavender (EDTA) - Whole Blood

Minimum Volume

0.5 mL Lavender (EDTA) - Whole Blood

Other Acceptable Specimens

Dark Green Top (Sodium Heparin) - Whole Blood
Yellow Top (ACD) - Whole Blood
Bone Marrow

Transport Temperature

Room Temperature

Specimen Stability

Room Temperature: 3-5 days

Methodology
The immunoglobulin heavy-chain gene variable region (IgVH) somatic hypermutation analysis is performed using extracted patient RNA as starting material. Subsequent amplification of the IgH gene is performed by polymerase chain reaction (PCR). The PCR products are isolated and sequenced. The nucleotide sequence is compared to a consensus germline sequence data base for that VH gene family. The results are reported as percentage of homology between the patient's VH sequence in comparison with the germline VH sequence using the Basic Local Alignment Search Tool (BLAST) for the Immunoglobulin data base at http://www.ncbi.nlm.nih.gov/igblast.

Report Available

6-8 days

Limitations

This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.

Clinical Significance

Determines the mutation status of IgVH gene in B lymphocytes, including those of CLL (chronic lymphocytic leukemia). The IgVH gene mutation status is one of the discriminators of clinical outcome in patients with CLL. The mutational status of the immunoglobulin genes expressed by CLL cells can be used to segregate patients into two subsets that have significantly different tendencies for disease progression. Patients with leukemic cells that express unmutated immunoglobulin heavy-chain variable region genes have a greater tendency for disease progression than those who have leukemic cells that express IgVH genes with less than 98% nucleic acid homology with their germ-line counterparts.

Performing Laboratory
LabCorp

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.