Silent mother-to-child transmission of hepatitis C virus through two generations determined by comparative nucleotide sequence analysis of the viral cDNA.

To investigate the routes of transmission of hepatitis C virus (HCV), a family in which HCV was considered to be transmitted from mother to child through two generations was studied. By the polymerase chain reaction method, HCV cDNA was isolated from the serum of a female baby with self-limited hepatitis C. HCV cDNA was also obtained from her mother and grandmother, who are healthy carriers of HCV, as well as from her uncle suffering from chronic persistent hepatitis C. The nucleotide sequence of the HCV cDNA fragment obtained from the baby was identical to that of the mother and was much closer to those of the grandmother and the uncle than to HCV cDNA isolates previously obtained from other Japanese patients or carriers. These results indicate the presence of mother-to-child transmission of HCV and suggest a role of this transmission route in establishing HCV carriers and maintaining a high incidence of HCV infection.