Interleukin 28B (IL28B) Variant (rs12979860), Varies
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
Multiple genotype tests may be performed from a single specimen after one extraction; consult the “Multiple Genotype Test List” for co‑orderable tests. Informed consent is required for New York State clients and must be documented on the request form or electronic order. Specific kit instructions apply for saliva collection. A previous allogeneic bone marrow transplant may interfere with results — contact Mayo Clinic Laboratories for guidance in such cases.
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.
New York Approved
Methodology
PCR-based (PCR)
Biomarkers
LOINC Codes
- 60279-7
- 60279-7
- 69047-9
- 48767-8
- 85069-3
- 62364-5
Result Turnaround Time
3-7 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
Not provided
Container
Lavender top (EDTA)
Collection Instructions
Invert several times to mix blood. Send whole blood specimen in original tube. Do not aliquot.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 days |
| Refrigerated | 4 days |
| Frozen | 4 days |