Περίληψη:
Three genotypes of hepatitis delta virus (HDV) have been identified,
each with different geographic distributions and disease associations.
To better define the geographic distribution and genetic variability of
HDV genotype I, and to evaluate the extent of genome variability in
populations with different patterns of HDV infection, we have analyzed
the sequence of Nov RNA in the sera of 72 patients from different areas.
Patients were primarily residents of the United States and areas in and
around Greece, including Archangelos, Rhodes. All sequences obtained
belonged to HDV genotype I, confirming the wide geographic distribution
of this genotype and its predominance in Europe and the United States.
In contrast to previous studies, phylogenetic analysis of this large and
diverse group of sequences, along with all available previously
published HDV sequences, showed no well-defined subtypes within genotype
I. Low sequence diversity was found for isolates from the United States,
Archangelos, Turkey, and Albania, suggesting that HDV was introduced
more recently and/or from fewer sources into these areas as compared to
mainland Greece, Italy, and north Africa, where sequence diversity is
much greater. The low sequence diversity among isolates from Archangelos
is particularly interesting in light of the unusually mild pattern of
HDV disease found in this community. Comparison of nucleic acid and
amino acid sequences within and among genotypes indicated both highly
conserved regions as well as genotype-specific sequences that could be
related to functional differences. The most distinctive of the latter
was that corresponding to the C-terminal 19-20 amino acids of the long
form of hepatitis delta antigen, which is highly conserved within each
genotype but considerably diverged among them. (C) 1997 Academic Press.
Συγγραφείς:
Shakil, AO
Hadziyannis, S
Hoofnagle, JH
DiBisceglie, AM and
Gerin, JL
Casey, JL
