Leprosy susceptibility genes reported

December 16, 2009

In the first genome-wide association study (GWAS) of leprosy and the largest GWAS on an infectious disease, scientists at the Genome Institute of Singapore (GIS) and 26 institutes in China identified seven genes that increase an individual's susceptibility to leprosy.

The discovery of these genes, reported in the 16 Dec. 2009 , highlights the important role of the innate immune response in the development of , said the scientists, who analyzed over 10,000 samples from leprosy patients and healthy controls in China.

"Though leprosy is not common, the discoveries have significant ramifications for chronic infectious disorders and for host-pathogen interactions in other more prevalent mycobacterial diseases such as tuberculosis, said Edison Liu, M.D., Executive Director of GIS, one of the research institutes sponsored by Singapore's Agency for Science, Technology and Research (A*STAR).

"This study represents one of the largest and best organized studies of the host genetics in published," added Dr. Liu.

An immunologist who was not one of the authors of the NEJM paper, Tom H. M. Ottenhoff, M.D., Ph.D., of Leiden University Medical Center in The Netherlands, said,

"This is a very impressive study, which uncovers entirely new genes that control susceptibility to leprosy and perhaps also other related diseases. A great asset is that the study underpins the genetic data with plausible functional biology experimentation, which is not often seen."

Dr. Ottenhoff is Professor in Immunology, Head group Immunology and Immunogenetics of Bacterial Infectious Diseases, at Leiden University Medical Center.

The seven genes associated with susceptibility to leprosy are: CCDC122, C13orf31, NOD2, TNFSF15, HLA-DR, RIPK2 and LRRK2.

"This is a very significant find, and one that can only be achieved through large-scale genetic studies, with close collaborative efforts among multi-disciplinary research groups, often across different countries," said Jianjun Liu, Ph.D., Human Genetics Group Leader at the GIS.

"The discovery of these genes is a major breakthrough for research in leprosy and infectious diseases in general, and will be significant in the early diagnosis and development of new treatments," added Dr. Liu.

In addition to Dr. Liu, the leaders of the GWAS on leprosy included: Fu-Ren Zhang, M.D., Ph.D., of Shandong Provincial Institute of Dermatology and Venereology, and Xue-jun Zhang, M.D., Ph.D., of Institute of Dermatology and Department of Dermatology at No.1 Hospital, Anhui Medical University, China.

GIS Executive Director Dr. Liu noted, , "This is a continuation of a number of deep collaborative studies between the GIS and Chinese scientists in using population sciences to uncover genetic modifiers of human disease. The strength of Chinese clinical sciences and of Singapore's targeted genomic capabilities makes a powerful scientific combination. The key to this collaboration and one that was recently published on the genetics of Asian migration is that the studies were initiated and executed by Asian partners acting as equals. Hopefully, this will initiate a new phase of cooperation between historically competing Asian countries whose primary links have been with western communities."

Leprosy, a chronic infectious disease caused by the bacterium Mycobacterium leprae (M. leprae), mainly affects skin and peripheral nerves and may lead to irreversible disabilities. Although it has been largely eliminated in developed countries, leprosy is still a major public health problem in many developing countries, particularly in tropic and sub-tropic regions. According to the World Health Organization, 254,525 new cases of leprosy were diagnosed in 2007. Although many people are potentially exposed to M. leprae in endemic regions, only a small minority will be infected and will develop clinically overt leprosy, suggesting that only some individuals are susceptible to this disease.

Because M. leprae cannot be cultured in the laboratory, and because it only infects humans and the Armadillo, research and thus the biological understanding of leprosy are very limited. The discovery of the seven susceptibility genes not only improves scientists' understanding about genetic susceptibility to the disease, but also may stimulate additional biological and clinical research to reveal the mechanism of leprosy development.

Explore further: AIDS drugs reveal leprosy infections

More information: "Genomewide association study of leprosy", New England Journal of Medicine, 16 Dec 2009.

Related Stories

AIDS drugs reveal leprosy infections

October 24, 2006

Experts in New York and around the world have said antiretroviral treatments have revealed hidden cases of leprosy in some AIDS patients.

First confirmed common genetic risk factors for breast cancer

May 29, 2007

The most powerful genetic analysis of the DNA codes of over 40,000 women -- including those with breast cancer as well as those without the disease – has uncovered five common genetic variants that increase an individual’s ...

Forgotten, but not gone: Leprosy still present in the US

November 7, 2008

Long believed to be a disease of biblical times, leprosy, also known as Hansen's disease, continues to be seen in the United States. "Approximately 150 cases are diagnosed each year with 3,000 people in the U.S. currently ...

Researchers identify new leprosy bacterium

November 24, 2008

A new species of bacterium that causes leprosy has been identified through intensive genetic analysis of a pair of lethal infections, a research team reports in the December issue of the American Journal of Clinical Pathology.

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

(PhysOrg.com) -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.