T300A genetic polymorphism: a susceptibility factor for Crohn's disease?

CONTEXT: Crohn's disease is characterized by a chronic and debilitating inflammatory disorder of the gastrointestinal tract. Several factors may contribute to its development. From extensive studies of the human genome, the polymorphism T300A of the gene ATG16L1 (autophagy-related 16-like 1) has been related to increased risk of developing this disease. OBJECTIVES: Analyze the role of polymorphism T300A (rs2241880) in patients with Crohn's disease. METHODS: 238 samples from (control group) and 106 samples from patients with Crohn's disease recruited at five Southern Brazilian reference centers were evaluated. The genotyping consisted of the amplification via Polymerase Chain Reaction of the genomic segment encompassing T300A, followed by Restriction Fragment Length Polymorphism analysis. The amplicons and fragments were separated by agarose gel electrophoresis and confirmed under ultraviolet light. RESULTS: The genotype AG was more prevalent among patients and controls (50% vs 44.8%), followed by genotypes AA (26.4% vs 35.1%) and GG (23.6% vs 20.1%). The frequency of the allele G of the polymorphism T300A was higher in the group of patients with Crohn's disease (48.6%) than in controls (42.4%), although not reaching statistical significance. CONCLUSIONS: It was not possible to confirm the increased susceptibility on development of Crohn's disease conferred by polymorphism T300A.