Table 1.

Recently published CMV UL97 kinase mutations that decrease drug susceptibility

Amino acid change	Fold increase EC501 for		Reference	Circumstances of detection2
	Ganciclovir	Maribavir
F342S	7.8	18	[12]	in vitro, cyclopropavir
V356G	5.5	108	[12]	in vitro, cyclopropavir minor subpopulation
D456N	12	278	[15]	in vitro, methylenecyclopropane nucleoside
C480R	9	243	[15]	in vitro, methylenecyclopropane nucleoside
C518Y	12		[16]	clinical isolate
P521L	17	428	[12]	clinical specimen, genotypic test result
A613V	2.3		[14]	clinical specimen, genotypic test result
Y617del3	10	372	[15]	in vitro, methylenecyclopropane nucleoside
E655K	1.7		[13]	clinical specimen, genotypic test result

¹Increase in drug concentration required to reduce viral growth 50% (EC50) compared with wild type

²Partial or complete mutant populations in clinical specimens or after in vitro passage under drug

³In frame deletion of codon 617