AsianScientist (May 30, 2012) – A liver biopsy and genetic analysis on a mummified Korean child by an Israeli-South Korean research team has revealed a unique hepatitis B virus genotype C2 sequence common in Southeast Asia.
The reconstruction of the ancient hepatitis B virus genetic code is the oldest full viral genome described in the scientific literature to date. The study is reported in a recent edition of the journal Hepatology.
Additional analysis of the ancient HBV genomes may be used as a model to study the evolution of chronic hepatitis B and help understand the spread of the virus, possibly from Africa to East Asia.
It also may shed further light on the migratory pathway of hepatitis B in the Far East from China and Japan to Korea as well as to other regions in Asia and Australia where it is a major cause of cirrhosis and liver cancer.
Carbon 14 tests of the clothing of the mummy suggests that the boy lived around the 16th century during the Korean Joseon Dynasty. The viral DNA sequences recovered from the liver biopsy enabled the scientists to map the entire ancient hepatitis B viral genome.
Using modern-day molecular genetic techniques, the researchers compared the ancient DNA sequences with contemporary viral genomes disclosing distinct differences. The changes in the genetic code are believed to result from spontaneous mutations and possibly environmental pressures during the virus evolutionary process.
Based on the observed mutations rates over time, the analysis suggests that the reconstructed mummy’s hepatitis B virus DNA had its origin between 3,000 to 100,000 years ago.
The hepatitis B virus is transmitted through the contact with infected body fluids, i.e. from carrier mothers to their babies, through sexual contact, and intravenous drug abuse.
According to the World Health Organization, there are over 400 million carriers of the virus worldwide, predominantly in Africa, China, and South Korea, where up to 15 percent of the population are carriers of the virus. In recent years, universal immunization of newborns against hepatitis B in Israel and in South Korea has led to a massive decline in the incidence of infection.
The article can be found at: Bar-Gal GK et al. (2012) Tracing hepatitis B virus to the 16th century in a Korean mummy.
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Source: Hebrew University of Jerusalem.
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