title: Spontaneous clearance of chronic hepatitis C infection is associated with an internal ribosomal entry site IIId stem loop structure variant.
abstract: OBJECTIVE
  To investigate if any mutations in hepatitis C virus (HCV) internal ribosome entry site (IRES) can inhibit the translation of viral polyprotein.
  
  
  METHODS
  A 26-year-old male patient infected with HCV 10 years ago was followed up. After 9 years of chronic infection. The patient had managed to resolve the infection for a period of 9 months, after which the patient experienced a viral recurrence characterized by high viral load and diverse HCV quasispecies. The IRES structures of the viral strains that disappeared were comparable with those that are currently active using structural mutational analysis.
  
  
  RESULTS
  A novo mutational position 254 combined with a rarely observed mutation at position 253 in the stem of the IIId subdomain were observed and the new conformation had an octa-apical loop (AGUGUUGG) and a shift in the 3 ` GU from the loop to the stem.
  
  
  CONCLUSIONS
  These mutations were found to be highly deleterious, and they affected the direct binding of the IIId loop to the 40S ribosomal subunit with a subsequent inhibition of translation of viral polyprotein and clearance of the virus.
authors: Department of Microbial Biotechnology , National Research Center, Tahrir, Dokki, Cairo, Egypt.
authors: N G
authors: NG
authors: Bader El Din
authors: M M
authors: MM
authors: El Hefnawy
authors: M H
authors: MH
authors: Omran
authors: R M
authors: RM
authors: Dawood
authors: Y
authors: Y
authors: El Abd
authors: M K
authors: MK
authors: Ibrahim
authors: M K
authors: MK
authors: El Awady
mesh_terms: D020121:5' Untranslated Regions; D000293:Adolescent; D001483:Base Sequence; D016384:Consensus Sequence; D004797:Enzyme-Linked Immunosorbent Assay; D016174:Hepacivirus / Q000235:genetics* / Q000276:immunology; D019698:Hepatitis C, Chronic / Q000175:diagnosis / Q000276:immunology / Q000821:virology*; D006801:Humans; D055029:Inverted Repeat Sequences; D008297:Male; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012367:RNA, Viral / Q000737:chemistry* / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D019562:Viral Load; D014766:Viremia
chemical_list: D020121:5' Untranslated Regions; D012367:RNA, Viral