Nq. Liu et al., MUTATIONS IN THE CYTOMEGALOVIRUS UL97 GENE ASSOCIATED WITH GANCICLOVIR-RESISTANT RETINITIS, The Journal of infectious diseases, 177(5), 1998, pp. 1176-1181
Vitreous from patients with cytomegalovirus (CMV) retinitis was studie
d in order to identify mutations in the CMV UL97 gene associated with
clinical resistance to ganciclovir. Point mutations known to confer re
sistance (V460, I460, V594, and S595) were found in 6 of 11 study eyes
. Rapid genetic screening by restriction enzyme analysis of viral DNA
amplified directly from the vitreous was as effective as conventional
sequencing in detecting these mutations. Repeat biopsy of 3 eyes revea
led no change in the UL97 genotype. The UL97 genotype differed between
eyes in 2 of 3 patients with bilateral, clinically resistant CMV reti
nitis. In summary, resistance mutations of the CMV UL97 gene are found
in the vitreous of some, but not all, eyes with CR IV retinitis that
have not responded to ganciclovir therapy. These mutations can differ
between eyes in patients with bilateral disease and can be rapidly det
ected using restriction digest analysis of polymerase chain reaction-a
mplified viral DNA.