Multiple infection of TT virus (TTV) with different genotypes in Japanese hemophiliacs

To clarify the persistent TT virus (TTV) infection, we studied a possibilit y of multiple TTV infection by genotype analysis of isolated TTV obtained f rom seven Japanese hemophiliacs. The nucleotide sequences including 222 bp in the open reading frame 1 (ORF1) region of 10 TTV isolates from each pati ent were analyzed and classified into various TTV genotypes such as G1 to G 6 by phylogenetic analysis using a N-J method. Multiple TTV genotypes were observed in all the hemophiliacs: three different TTV genotypes were found in three patients, whereas four different ITV genotypes were observed in th e other three patients. The remaining patient was also infected with TTV of five different genotypes. Moreover, new TTV genotypes were found in these seven patients and tentatively designated as G7. The present findings indic ate that multiple TTV infect-ion with different TTV genotypes has occurred in Japanese hemophiliacs. They also provide valuable information to underst and persistent TTV infection. (C) 1999 Academic Press.