Emergence of Multiple Human Cytomegalovirus Ganciclovir-Resistant Mutants with Deletions and Substitutions within the UL97 Gene in a Patient with Severe Combined Immunodeficiency

Infection with multiple ganciclovir-resistant human cytomegalovirus mutants, containing different substitutions and deletions in the UL97 gene, was found in a patient with severe combined immunodeficiency (SCID) within 3 weeks of ganciclovir therapy. A novel 11-codon deletion at positions 590 to 600 was identified. These unique findings may be related to the nature of the immunodeficiency in the SCID patient.