MedWire News: An international team of researchers has identified many novel genetic links to the development of Crohn's disease, and confirmed that previously identified genes play a role in the development of the inflammatory bowel disease.
"This greatly increases our knowledge of the genetic architecture of Crohn's disease and gives us more detailed insight into the biological underpinnings of the disease," said lead researcher Dr Mark Daly, from Harvard Medical School in Boston, Massachusetts, USA.
"Better understanding of the precise functions of these genes and the molecular effects of Crohn's-associated variants should lead us to novel strategies for therapies and, someday, prevention."
Dr Daly and colleagues previously identified 11 genes associated with the development of Crohn's disease. However, the search for other genes associated with the condition was hampered by the relatively small number of patients in the original analysis, says the team.
In the current study, the researchers pooled genetic data from three previously published studies involving 3230 patients with Crohn's disease and 4829 without the inflammatory bowel condition.
This was supplemented by an examination of new data from an additional 3700 people with and without the disease.
The team's analysis confirmed the role of the 11 previously identified genes in the development of Crohn's disease, and also identified another 21 genes that may play a role in the development of the condition.
Many of these genes are involved in immune system processes, and particular variations may combine to cause the immune system overreaction that is a characteristic of Crohn's disease, say the researchers.
"It's amazing that all of the genes identified in genome-wide association studies of Crohn's so far align with the pathways that we know are disrupted, systems that sense the presence of microbes and effectively clear them from the body," commented co-researcher Dr Ramnik Xavier, also from Harvard Medical School.
He concluded: "Mapping the internal circuitry of these systems and identifying the molecular switches that control those circuits should lead to better targeted drugs for Crohn's and other inflammatory bowel diseases."
The research is published in the journal Nature Genetics.