Objective: To investigate the polymorphism of human cytomegalovirus(HCMV) UL135 gene in the low passage clinical isolates and to study the relationship between the polymorphism and diseases caused by congenital HCMV infection.Methods: The entire HCMV UL135 gene regions of 29 clinical isolates in which positive HCMV-DNA was detected by using fluorescence quantitative polymerase chain reaction(FQ-PCR) were amplified by polymerase chain reaction(PCR).Amplified PCR products were sequenced,and the sequence were ...