Objective: To analyse the possible influence of a non-synonymous single nucleotide polymorphism (SNP) of the histamine-degrading enzyme diamine oxidase (DAO) on genetic susceptibility to Crohn's disease (CD).
Material and methods: In this prospective, case-control study, 210 unrelated Caucasian consecutive CD patients were recruited at the Inflammatory Bowel Disease Unit of a single tertiary centre (Hospital Clínico San Carlos) in Madrid, Spain. A total of 261 healthy volunteers from the same geographic area were also recruited and matched with patients. Both cases and controls were analysed for the presence of a non-synonymous SNP (rs1049793) of DAO using amplification-restriction procedures of the genotype obtained in a blood sample.
Results: No significant differences were found in the distribution of carriers of the non-synonymous SNP of DAO between CD patients and controls (OR 1.2 (95% CI 0.9-1.6; p=0.3)). Nor were any differences found between carriers and non-carriers of the non-synonymous SNP in demographic characteristics, phenotypes, complications or treatment of CD.
Conclusions: The study of a non-synonymous SNP (rs1049793) of DAO does not seem to be of use in assessing susceptibility to CD, either as a marker of disease activity or as a marker of clinical behaviour in patients with the disease.