Backg round/ Aims : The distribut ion of HCV genotypes varies with geographical area, and genot ypes can affect t he nat ur al course of HCV infection, but adequate genot yping data were not accumulat ed in Korea. This study was des igned to det ermine the pattern of distribution of HCV genotypes in Korea and it's clinical implications . Methods : 100 cons ecut ive anti- HCV( +), RT - PCR(+) cases were recruited. Genotype specific oligonucleotide primers were made according to the sequence variation of NS5 region of HCV genome. Heminested PCR with mixed primersets was per formed, and genotype specific PCR products of different size were verified. Sequencing of cloned PCR products was done in cases with representative genotypes . Clinical profiles of genotype 1b and 2a were compared. Results : Genotyping was done in 78 among 100 cases. Genotype 1b (48/ 78, 57.7%) and 2a (25/ 78, 32.1%) were most prevalent , and 1a (1/ 78, 1.3%) and mixed form (7/ 78, 9.0%) were also found. Milder cases with persistent normal ALT levels were more frequently seen in genotype 2a ( 9/ 25, 36.0%) than in genot ype 1b (3/ 45, 6.7%) (p< 0.01). Conclusions : Genotype 1b and 2a were major ones in anti- HCV( +) Korean adults , and the tendency of milder clinical course of genotype 2a was suggested. (Korean J Hepatol 1998;4:235-243)
