A single gene would determine the risk of developing Crohn's disease

The researchers have managed to identify a single gene that can increase or decrease the risk of developing Crohn's disease. This same gene could also be involved in Parkinson's disease.

Crohn's disease is a chronic and serious inflammatory disease. It mainly affects the small intestine and the large intestine to the anus. This is due to an autoimmune response that leads to excessive and painful inflammation in the lining of the intestines. Tissue surrounding the digestive system becomes thick and can even lead to ulcerations and fistulas that can lead to the removal of the parts of the gut that cause the problem.
Researchers analyzed the genomes of 5,700 Ashkenazi Jews - sick and non-sick - 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 increase or decrease the risk of developing Crohn's disease.

The LRRK2 gene in question

It turns out that if a person has the "wrong" variant of the LRRK2 gene, his risk of illness is 70%, compared to 25% for those who have had the "good" variant. It turns out that this gene plays a role in eliminating accumulated waste in a type of white blood cell called macrophage as well as in some stem cells that are found in the small intestine. This study was published in Science Translational Research.

Researchers suspect that this waste damages cells and causes inflammation. In addition, this same gene has also been implicated with Parkinson's, which means that any treatment could help both diseases.