Sign in →

Test ID CMVNG Cytomegalovirus (CMV) Drug Resistance, Next-Generation Sequencing, Plasma

Ordering Guidance

This test is not intended for the initial diagnosis of cytomegalovirus (CMV) infection. If a diagnostic test is needed, order CMVQN / Cytomegalovirus (CMV) DNA Detection and Quantification by Real-Time PCR, Plasma.


Next-generation sequencing testing may be indicated if a patient with known CMV infection has a rising, or stabilizing, viral load while on antiviral therapy. This test can assist in determining whether CMV is present that has acquired mutations (variants) associated with antiviral resistance and should only be performed on patients who have had a recent (ie, within the previous 7 days) CMV quantitative plasma viral load of 500 IU/mL or greater.


Testing for CMV resistance should be performed no more frequently than once every 4 weeks.


Changes in CMV viral load 0.5 log or greater are considered significant and may prompt testing for antiviral resistance if the patient is on appropriate therapy.

Additional Testing Requirements

Plasma submitted for next-generation sequencing (NGS) testing must have been collected within 7 days of a viral load assay (CMVQN / Cytomegalovirus [CMV] DNA Detection and Quantification by Real-Time PCR, Plasma or similar test) with a result of 500 IU/mL or greater.

Shipping Instructions

1. Freeze plasma specimen immediately, and ship specimen frozen on dry ice.

2. If shipment will be delayed for more than 14 days, freeze plasma specimen at -20 to -80° C (up to 30 days) until shipment on dry ice.

Specimen Required

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube: Lavender top (EDTA)

Submission Container/Tube: Plastic vial

Specimen Volume: 1.2 mL

Collection Instructions: Centrifuge and aliquot plasma into a plastic vial.

Additional Information: Plasma for next-generation sequencing must be collected within 7 days of a viral load assay (ie, CMVQN) with a result of 500 IU/mL or greater.

Useful For

Detecting mutations (variants) in the cytomegalovirus genes, UL97 and UL54, which are associated with antiviral resistance


This test is not useful for the initial diagnosis of CMV infection

Testing Algorithm

This test may be performed following quantitative nucleic acid amplification test results that suggest an increase, or stabilization, of cytomegalovirus viral load while the patient is on appropriate antiviral therapy.

Method Name

Next-Generation Sequencing (NGS)

Reporting Name

CMV Antiviral Resistance by NGS, P

Specimen Type

Plasma EDTA

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma EDTA Frozen (preferred) 30 days
  Refrigerated  14 days

Reference Values

None Detected/Not Predicted

Day(s) Performed


Report Available

16 to 20 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
CMVNG CMV Antiviral Resistance by NGS, P 72852-7


Result ID Test Result Name Result LOINC Value
604560 CMV UL97 mutations 72833-7
604561 CMV UL54 mutations 33631-3
604562 Ganciclovir Resistance 72854-3
604563 Cidofovir Resistance 72856-8
604564 Foscarnet Resistance 42317-8
CMVQ1 CMV Quant >= 500 IU/mL last 7 days? 86955-2


If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.