TTC7A and multiple intestinal atresia: Patients with TTC7A deficiency typically present with features of severe combined immunodeficiency (SCID), along with severe exfoliative apoptotic enterocolitis.30, 37, 38 In previous studies, mutations in TTC7A were reported to have multiple intestinal atresias (MIA) possibly due to the constant inflammation and apoptosis of the epithelium.