IGH Somatic Hypermutation Analysis, B-Cell Chronic Lymphocytic Leukemia (B-CLL), Varies

Clinical Use

Use

Providing prognostic information in patients with newly diagnosed B-cell chronic lymphocytic leukemia. Clonal IGHV gene hypermutation status provides important prognostic information for patients with CLL and small lymphocytic lymphoma (SLL). The presence of IGH SHM is defined as greater than 2% difference from the germline VH gene sequence identity (mutated), whereas less than or equal to 2% difference is considered no SHM (unmutated). The status of SHM has a clear influence on the median survival of CLL patients.

Special Instructions

Not provided.

Limitations

This test is not intended for use in providing prognostic information for patient with other B-cell neoplasms or hematopoietic tumors. This test requires a minimum monoclonal CLL B-cell percentage in order to amplify the clonal IGH gene rearrangement. This level has been established at 5% of lymphocytes (e.g., as determined by flow cytometric immunophenotyping). A CLL population below 5% will not have a reliable or reproducible clonal gene rearrangement. The prognostic significance of somatic hypermutation (SHM) status is only known when a single functional IGH rearrangement is identified. Rearrangements containing a variation frequency of greater than 2% are interpreted as mutated. Rearrangements containing a variation frequency less than or equal to 2% are interpreted as unmutated.

Test Details

New York Approved