A novel ganciclovir resistance mutation in the UL97 gene of the HHV-5 in an adult hematopoietic stem cell transplant recipient

Therapeutic management of cytomegalovirus (CMV) disease in hematopoietic stem cell transplantation patients can become a challenge because of the emergence of anti-CMV drug resistance. This case report presents a patient with clinical ganciclovir resistance due to a new mutation: histidine-to-asparagine change at residue 393 of UL97. This mutation, which is located in the nonfunctional region of the UL97 gene, is very unusual. Having more information about the mutations leading to drug resistance in CMV is important for both improved clinical management and development of new diagnostic tests and drugs.