Comprehensive epidemiological and genotype-phenotype analyses in a large European sample with idiopathic achalasia.

Background And Aim: Although an eight-residue insertion in HLA-DQβ1 has been recently identified as a genetic risk factor for idiopathic achalasia, other risk factors are still unknown. In the present study, we carried out an epidemiological survey and a genotype-phenotype (G×P) analysis to gain further insights into the etiology of achalasia.

Methods: We obtained medical data from 696 achalasia patients and 410 controls, as well as their first-degree relatives (2543 of patients and 1497 of controls).