No genetic association between EPHX1 and Crohn’s disease

In a case control study on the associations between functional genetic polymorphisms in biotransformation enzymes and Crohn’s disease, we found a strong association between the Tyr113His (348T>C) polymorphism in exon 3 of the microsomal epoxide hydrolase (EPHX1) gene and Crohn’s disease.1 The three referees all agreed that the study was interesting and should be published so that other groups can attempt to replicate the results in independent study cohorts. This was done recently by Cuthbert and colleagues ( Gut 2004; 53 :1386) who investigated 344 controls and 307 patients with Crohn’s disease, and who were unable to reproduce our results. In addition, they reported that our data for the EPHX1 exon 3 polymorphism in the control group were not in Hardy-Weinberg equilibrium (HWE), as also noticed previously by Gyorffy and colleagues.2 Our data on EPHX1 exon 3 genotyping were obtained by restricted fragment length polymorphism (RFLP) analyses by applying the method described by Lancaster and colleagues.3 However, recently it was reported that a silent substitution polymorphism (G to A) …