HLA-DQA1 and Achalasia: Some studies have been shown genetic correlations in achalasia, for example, ALADIN gen associated with Allgrove syndrome, receptor of vasoactive intestinal polypeptide (VIPR1) gene polymorphism, interleukin- (IL-) 23 receptor polymorphism, protein tyrosine phosphatase nonreceptor 22 gene polymorphism, and human leukocyte antigen- (HLA-) DQβ1 (HLA-DQB1∗05:03  and HLA-DQB1∗06:01), HLA-DQα1 (HLA-DQA1∗01:03), and HLA-DQβ1 (HLA-DQB1∗03:01 and HLA-DQB1∗03:04) [8].