[Sequence variability in Borna disease virus ORF II from human beings].

40 clones from five psychiatric patients and three healthy blood donors in whom Borna disease virus (BDV) ORF II fragments in PBMC were previously proved by nested RT-PCR were sequenced and compared with BDV/MDCK. There were eleven point mutations in all clones compared with reported HE80-1, but no difference between human and BDV/MDCK clones. We found specific sequence variability at nt 1701 in ten clones from two psychiatric disorder patients (T-->C) and at nt 1696 in fifteen clones from three healthy blood donors (A-->T). This result strongly suggests there are some special gene divergence in BDV derived from human beings.