ATG16L1

Crohn's disease

At least one variation in the ATG16L1 gene is associated with an increased risk of Crohn's disease, particularly a form of the disorder that affects the lower part of the small intestine (the ileum) and the colon. This increased risk has been found primarily in people of northern European ancestry. The identified ATG16L1 variation changes a single protein building block (amino acid) in a critical region of the ATG16L1 protein. Specifically, it replaces the amino acid threonine with the amino acid alanine at protein position 300 (written as Thr300Ala or T300A).

This change in the ATG16L1 gene impairs the autophagy process, allowing worn-out cell parts and harmful bacteria to persist when they would otherwise be destroyed. These cell components and bacteria may trigger an inappropriate immune system response, leading to chronic inflammation in the intestinal walls and the digestive problems characteristic of Crohn's disease. Researchers continue to study the relationship between changes in the ATG16L1 gene and a person's risk of developing this disorder.