Interleukin 28B (IL28B) Variant (rs12979860), Varies

Clinical Use

Use

Individuals with hepatitis C virus (HCV) genotype 1 infection exhibit variable response to pegylated‑interferon and ribavirin therapy. The genotype at the rs12979860 single‑nucleotide variant near IL28B (IFNL3) is associated with treatment response: patients with CC genotype have approximately two‑ to three‑times higher rates of sustained viral response (SVR) than those with CT or TT genotypes, across European American, African American, and Hispanic populations. The CC genotype is also linked with a three‑fold increase in spontaneous clearance of HCV. These results are derived from aggregated clinical studies and should be interpreted alongside other clinical factors. Mutation testing is limited to rs12979860.

Special Instructions

Not provided.

Limitations

This test detects only the rs12979860 single‑nucleotide variant and does not assess other variants. Rare variants may produce false‑negative or false‑positive results. Specimens from individuals who have received non‑leukoreduced transfusions or allogeneic hematopoietic stem cell transplantation may contain donor DNA and may not reflect recipient genotype; genotype usually reverts to recipient within six weeks post‑transfusion. For transplant recipients, a pre‑transplant DNA specimen is preferred. Saliva yields lower DNA quantity/quality than blood and may reduce assay performance; missing regions may be noted and additional specimens may be required.

Test Details

New York Approved