HONG KONG Scientists in Japan have identified a series of gene mutations that appear to make people more susceptible to chronic hepatitis B infection.
An estimated 400 million people are chronically infected with hepatitis B worldwide. Nearly 60 percent of liver cancers are related to chronic hepatitis B and liver cirrhosis, or scarring.
In a letter published in Nature Genetics, the researchers said they analyzed the genes of groups of hepatitis B patients and compared these with the genes of other participants who were free of the disease.
They said the hepatitis B patients had 11 genetic mutations in a region that includes the HLA-DPA1 and HLA-DPB1 genes.
"These genes are structurally similar to genes that encode proteins critical for launching an effective immune response against HBV (hepatitis B virus)," they wrote.
The researchers, headed by Yoichiro Kamatani at University of Tokyo's Human Genome Center, studied the genes of 786 Japanese with hepatitis B and 2,201 others without the disease.
The results were then compared against those of three other cohorts consisting a total of 1,300 hepatitis B patients and 2,100 healthy participants.
"Although disease prevalence is not determined solely by genetic factors, the findings presented in our manuscript suggest that genetic factors might exert substantial influence on the prevalence of infectious disease," they wrote.
They hoped their findings would push for the development of new therapies to treat the disease and prevent disease progression."
Scarring of the liver and liver cancer result in a combined 1.5 million deaths a year globally.
Hepatitis B is endemic in parts of Asia and Africa, and the chief mode of transmission is from mother to child. Worldwide, there are 400 million hepatitis B carriers and up to 130 million of those are in China. Between 10 and 17 percent of the Chinese population are carriers.
(Reporting by Tan Ee Lyn; Editing by Sanjeev Miglani)