CMV Drug Resistance, Rapid UL97, UL54 and UL56

CMV Drug Resistance: Ganciclovir, Cidofivir, Foscarnet and Letermovir (UL54, UL97 and UL56 genes).

Mutations leading to CMV drug resistance have been described in the UL97 gene (phosphotransferase encoding region), UL54 gene (DNA polymerase encoding region) and the UL56 gene (is part of the viral terminase complex that also includes components encoded by the UL89 and UL51genes) of the CMV genome.

Mutations associated with resistance to Ganciclovir have been described in the UL97 gene. Genotypic analysis is performed by Sanger sequencing two overlapping amplicons of about 350bp of the 3’ end of the UL97 gene.

Mutations associated with resistance to Ganciclovir, Cidofivir and Foscarnet have been described in the UL54 gene. Genotypic analysis is performed by Sanger sequencing a 1kB region of the UL54 gene.

Mutation associated with resistance to Letermovir have been described in the UL56 gene. Genotypic analysis is performed by Sanger sequencing about 700bp towards the 5’ end of the UL56 gene.

The minimum virus level that gives a sequencable PCR amplicon is 240 IU/mL (2.4 log IU/mL).

Specimens with undetectable CMV viral load are rejected.

This test was developed and its performance characteristics determined by the University of Washington Department of Laboratory Medicine and Pathology. It has not been cleared or approved by the US Food and Drug Administration.

For UL97 and UL54 CMV gene sequencing, see CMV UL97 and UL54 Drug Resistance Seq [CMVDRS].

For UL56 CMV gene sequencing, see CMV Letermovir Resistance, UL56 [CMVDRL].