A team of scientists from Singapore and China have identified two new genes associated with the spine disease known as Ankylosing Spondylitis (AS). This discovery brings scientists closer to understanding the disease, enabling them to work toward a cure.
Ankylosing Spondylitis is a progressive auto-immune disease characterized by chronic inflammatory back pain, often accompanied by peripheral arthritis and iritis. The disease can eventually lead to spine fusion, also known as “bamboo spine”.
Ankylosing Spondylitis effects .024 percent of the Chinese population, with an estimated genetic heritability of over 90%. Similar to that in populations of European ancestry.
The gene HLA-B27 had previously been linked with AS susceptibility, but it confers only 20-30% of the overall genetic risk.
In order to identify other genes associated with AS, the researchers carried out a large genome-wide study in the Chinese Han population.
Initially, they performed a comprehensive genome-wide analysis of common genetic variants in 1,837 AS patients 4,231 without Ankylosing Spondylitis. Subsequently, selecting 30 genes for a validation study in an additional 2,100 patients and 3,496 controls.
The researchers discovered two new genes responsible for Ankylosing Spondylitis – EDIL3-HAPLN1 on 5q14.3 and ANO6 on 12q12 – which are related to bone formation and cartilage development. The discovery suggests their potential involvement in the development of AS.
The study also confirmed the previously reported association with HLA-B27 and Ankylosing Spondylitis.
Dr Liu said: “AS is an autoimmune disease, and the association of HLA-B*27 is not surprising. Our study confirms the important role of the immunity, but more importantly, it indicates that other mechanisms, such as bone formation and cartilage development also play an important role in AS.”
The study was reported in the advanced online issue of Nature Genetics on 4 December 2011 under the title “A genome-wide association study in Han Chinese identifies new susceptibility loci for Ankylosing Spondylitis”. Research ream headed by Dr Liu Jianjun Senior Group Leader and Associate Director of Human Genetics at the Genome Institute of Singapore (GIS) and Dr Gu Jieruo rheumatologist at the 3rd Affiliated Hospital of the Sun Yat-Sen University.
Information provided by: Agency for Science, Technology and Research (A*STAR), Singapore
Other genes that are associated with Ankylosing Spondylitis: See NCBI citations: ” A genome-wide association study in Han Chinese identifies new susceptibility loci for ankylosing spondylitis.,” “Genome-wide association study of ankylosing spondylitis identifies non-MHC susceptibility loci.,” ” Is there a higher genetic load of susceptibility loci in familial ankylosing spondylitis?,”