TTC7A and immune system disorder: GIDID is characterized by intestinal atresia and immunodeficiency, and thus two subtypes have been identified until now—GIDID1 (OMIM: 243150) and GIDID2—caused by mutations in the TTC7A and PI4KA genes, respectively, surprisingly concerning in which the GIDID-related two genes were on the kinase PI4KIIIa-TTC7-FAM126-EFR3 complex.