title: High prevalence of hepatitis B virus genotype C/C1 in the Minangkabau ethnic group in Indonesia.
abstract: BACKGROUND
  The Minangkabau is one of the major ethnic groups in Indonesia. Previous studies with a limited number of samples have shown a different prevalence of HBV/C in the Minangkabau compared to the Indonesian population in general. The aim of this study was to assess the HBV genotype distribution pattern and the prevalence of pre-S, T1753V and A1762T/G1764A mutations among the Minangkabau HBV carriers. The samples were collected from Padang, West Sumatera and from western Java. Mixed primers for specific genotypes were used to determine the HBV genotype. Pre-S or S genes were amplified, sequenced and aligned with reference sequences from GenBank to derive a phylogenetic tree for subgenotyping. Pre-S genes were also analyzed for mutations. The basal core promoter (BCP) region was amplified and directly sequenced to analyze T1753V and A1762T/G1764A mutations.
  
  
  RESULTS
  The predominant HBV genotype among the Minangkabau HBV carriers (n=117) was C (72.6%) followed by B (24.8%) and co-infection with B and C (2.6%). The prevalence of pre-S mutations, including both the pre-S deletion and pre-S2 start codon mutation, was 41.0%, and the T1753V and A1762T/G1764A mutations were found in 51.9% and 71.2% respectively. HBV/C1 was the predominant HBV subgenotype in the Minangkabau HBV carriers, and was found in 66.2%, followed by B3, B7, C8, B2, B9, C2, and C10 (18.3%, 7.0%, 2.8%, 1.4%, 1.4%, 1.4%, and 1.4% respectively). From samples that were found to be co-infected with HBV B and C, two samples were successfully cloned and subgenotyped, including one with mixed subgenotypes of B3 and C1, and another one with mixed subgenotypes of B7, C1, putative intergenotypic of B/A, and C/A. Furthermore, three samples from donors of non-Minangkabau ethnicity from Padang were found to be infected with an intragenotypic recombination form, including a putative recombinant of B8/B3 and B9/B7.
  
  
  CONCLUSIONS
  HBV/C with subgenotype C1 was the predominant HBV genotype among HBV carriers of Minangkabau ethnicity. The prevalence of pre-S, A1762T/G1764A, and T1753V mutations was higher among the Minangkabau compared to Indonesian HBV carriers in general.
authors: Molecular Epidemiology Division, Mochtar Riady Institute for Nanotechnology, Universitas Pelita Harapan, Lippo Karawaci, Tangerang, Indonesia.
authors: Marlinang D
authors: MD
authors: Siburian
authors: Andi
authors: A
authors: Utama
authors: Rama
authors: R
authors: Dhenni
authors: Null
authors: N
authors: Arnelis
authors: Ismail
authors: I
authors: Fanany
authors: Mariana D B
authors: MD
authors: Intan
authors: Tri S
authors: TS
authors: Kurniasih
authors: Febi
authors: F
authors: Andriani
authors: Szeifoul
authors: S
authors: Afadlal
authors: Erlys B
authors: EB
authors: Julianto
authors: Widyarman S
authors: WS
authors: Rasman
authors: Nasrul
authors: N
authors: Zubir
authors: George
authors: G
authors: Mathew
mesh_terms: D000328:Adult; D002353:Carrier State / Q000453:epidemiology / Q000821:virology; D016000:Cluster Analysis; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D005006:Ethnicity; D005260:Female; D005838:Genotype; D006509:Hepatitis B / Q000453:epidemiology* / Q000821:virology*; D006514:Hepatitis B Surface Antigens / Q000235:genetics; D006515:Hepatitis B virus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007214:Indonesia / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D015995:Prevalence; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA
chemical_list: D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens