Screening the DNA of nearly 5700 Jewish people has identified a gene that helps determine a person鈥檚 risk of developing Crohn鈥檚 disease. Different mutations in the same gene can make someone more likely to get the condition, or help protect them from ever developing it.
Crohn鈥檚 disease is the most serious form of inflammatory bowel disease. Current treatments for the condition frequently fail to provide much relief, and people with the disorder often have to have particularly inflamed regions of their gut removed surgically.
But understanding the genetics of the disease could lead to new treatments. , of the Mount Sinai School of Medicine in New York, and her team screened for genes involved in the disorder by studying DNA from Ashkenazi Jews 鈥� an ethnic group in which Crohn鈥檚 disease is up to three times more common.
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Parkinson鈥檚 link
Comparing the DNA from 2066 people with the condition and 3633 people without the disorder, the team identified two genetic variants of the same gene with differing effects. Called LRRK2, one variant of this gene raises a person鈥檚 risk of Crohn鈥檚 by 70 per cent, while the other variant lowered it by around 25 per cent.
This gene is normally active in macrophages 鈥� a type of white blood cell 鈥� and a kind of stem cell, both in the small intestine. It makes a protein that helps collect debris and waste inside a cell and eliminate it.
鈥淭he 鈥榖ad鈥� version of the gene impairs this waste disposal function, so garbage builds up, damaging the cell and leading to inflammation,鈥� says Peter.
By mimicking the 鈥済ood鈥� version of this gene, Peter鈥檚 team hope to develop new treatments for the disease. LRRK2 has also been implicated in Parkinson鈥檚 disease, so drugs targeting this gene may well help both diseases, says Peter.
