These findings show an association between BCL11B variants and “Immunodeficiency 49” and “Intellectual developmental disorder with dysmorphic facies, speech delay, and T‐cell abnormalities.” Interestingly, patients with missense variants tend to have a more severe immunodeficiency, which may be due to the loss of DNA binding (Lessel et al., 2018). Here, BCL11B is linked to immune system disorder.