To investigated the relationship between the sequence polymorphism and different signs of human cytomegalovirus（HCMV） disease

PCR was performed to amplify the entired HCMV UL131A

UL130

UL128 genes of eighteen low-passage clinical isolates and five non-passage strains from congenitally infected infants and PCR amplification products were sequenced directly.Comparisons were made between UL131A

UL130

UL128 genes of clinical strains and published sequences of Towne and Merlin strains.Detailed sequence analysis showed that the UL131A

UL130

UL128 genes were highly conserved in all clinical strains.The coding regions of clinical strains were identical in size.The nucleotide and amino acid sequence identities of UL131A

UL130

UL128 genes and their putative proteins among all strains were 96.2%

95.8%

96.0% and 97.2%

96.6%

96.9% respectively.The present study indicated that UL131A

UL130

UL128 genes of clinical strains from infants with different sign of HCMV disease showed similar structure.Sequence comparison indicated that UL130 and UL128 genes encoded chemokine-like protein in clinical strains.The conservation of the UL131A-128 loci is consistent with the conclusion that the three encoded proteins are all essential for growth of HCMV in endothelial cells and virus transfer to leukocytes.The presence of chemokine-like domains in UL130 and UL128 putative proteins suggests that the predicted products may play a role in HCMV infectivity.