RESUMEN
Objective To investigate the relationship between transfusion transmitted virus (TTV)infection and neonatal hyperbilirubinemia,the effect of TTV infection on the liver function, and analyse the feature of nucleotide sequences in TTV ORF1.Methods Serum TTV DNA,which were from 58 neonates with high direct bilirubin(DB,including 5 with hepatitis Syndrome),92 ones with high indirect bilirubin(IB),and 85 normal ones,was detected using a nested polymerase chain reaction technique(nPCR),electropherosis and sequence analyse,and serum alanine amniotransferase (ALT)was determined in all neonates.Results In DB neonates,TTV DNA were detected in 7 neo- nates(12.1%,including 3 neonates with hepatitis syndrome);in IB and normal ones,1 neonate had positive TTV DNA(1.1% and 1.25),respectively.Even if there were point mutations in Guangdong's TTV,the homology of Guangdong's TTV(GD1-9)and Japanese TTV(N22)ranged from 87.1%～97.8% at nucleotide level.Conclusion TTV infection may be one of important pathogenesis resulting in neonatal hyperbilirubinemia and liver damage in such patients.Guangdong's and Japanese TTV isolates had the same genotype,some gene mutations maybe increase the pathogenicity in TTV.