Researchers have managed to pinpoint a single gene that can either increase or decrease the risk that you will develop Crohn’s disease depending on which variant you happen to have. This very same gene might also be involved in Parkinson’s, meaning that doctors could kill two birds with one stone.

When it's not a Heinz sauce packet that was swallowed six years previously, Crohn’s disease is a serious inflammatory condition. Primarily affecting the digestive system, the condition is due to an autoimmune response that leads to excessive, painful, and long-term inflammation of the intestines and bowels.

The inflamed tissue surrounding the digestive system becomes thick and swollen, and can even lead to open sores developing. The chronic condition can flare up throughout a person’s life, and in serious cases, doctors may even decide to take quite drastic action and remove the sections of the intestine that are causing the issue.

The condition is thought to be down to a combination of genetic and environmental factors, although how they all come together is still a little hazy at the moment. It is thought that more than half a million Americans are affected by Crohn’s disease, and it tends to occur more often in people of northern European ancestry and Ashkenazi Jewish decent.

For this latest study, published in Science Translational Medicine, the researchers trawled through the genomes of 5,700 Jewish people – some with the condition and some without – to see if they could glean anything else about the underlying genetics of the disease.

They discovered that different mutations in the same gene could either increase or decrease a person’s risk of developing Crohn’s disease. It turns out that if a person has the “bad” variant of the LRRK2 gene, it raises a patient's risk of the condition by a hefty 70 percent, while for those who happened to have the “good” variant, their risk was cut by 25 percent.

It turns out that this gene plays a role in the elimination of waste that is built up in a type of white blood cell known as a macrophage as well as in some stem cells, both of which can be found in the small intestine. The researchers suspect that this waste is effectively damaging the cells and leading to inflammation.

Interestingly, this same gene has also been implicated with that of Parkinson's, meaning that any potential treatment could help both diseases.

[H/T: New Scientist]