title: Phylogenetic analysis of hepatitis B virus in Pakistan.
abstract: OBJECTIVE
  To identify the distribution pattern of Hepatitis B Virus (HBV) genotype in a group of patients and to study its phylogenetic divergence.
  
  
  METHODS
  An observational study.
  
  
  METHODS
  The clinics of Gastroenterology Unit, Ziauddin University, from January to December 2006.
  
  
  METHODS
  Two hundred and one HBV infected patients were genotyped for this study. All HbsAg positive individuals, either healthy carriers or suffering from conditions such as acute or chronic hepatitis, cirrhosis and hepatocellular carcinoma were included. Hepatitis B patients co-infected with other hepatic viruses were excluded. Hepatitis B virus DNA was extracted from serum, and subjected to a nested PCR, using the primers type-specific for genotype detection. Phylogenetic analysis was performed in the pre-S1 through S genes of HBV. The divergence was studied through 15 sequences of 967 bp submitted to the DBJ/EMBL/GenBank databases accessible under accession number EF584640 through EF584654.
  
  
  RESULTS
  Out of 201 patients tested, 156 were males and 45 were females. Genotype D was the predominant type found in 128 (64%) patients followed by A in 47 (23%) and mixed A/D in 26 (13%). Phylogenetic analysis confirmed the dominance of genotype D and subtype ayw2.
  
  
  CONCLUSIONS
  There was dominance of genotype D subtype ayw2. It had a close resemblance with HBV strains that circulate in Iran, India and Japan.
authors.affiliation: Department of Biochemistry, Ziauddin Medical University, Karachi. baigsaeeda@yahoo.com
authors.forename: Saeeda
authors.initials: S
authors.lastname: Baig
authors.forename: Anwar Ali
authors.initials: AA
authors.lastname: Siddiqui
authors.forename: Runu
authors.initials: R
authors.lastname: Chakravarty
authors.forename: Tariq
authors.initials: T
authors.lastname: Moatter
authors.forename: Tayyab
authors.initials: T
authors.lastname: Unnissa
authors.lastname: Nazr-ul-Hasnain
mesh_terms: D004279:DNA, Viral / Q000235:genetics; D005260:Female; D005838:Genotype; D006509:Hepatitis B / Q000097:blood / Q000453:epidemiology / Q000235:genetics*; D006510:Hepatitis B Antibodies / Q000235:genetics; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D008297:Male; D017720:Molecular Epidemiology; D009154:Mutation; D010154:Pakistan / Q000453:epidemiology; D010802:Phylogeny; D010865:Pilot Projects
chemical_list: D004279:DNA, Viral; D006510:Hepatitis B Antibodies