DNMT3B and Immunodeficiency: For instance, DNMT1 mutations are linked to hereditary sensory neuropathy type IE (HSANIE), mutations in DNMT3A are associated with overgrowth like Tatton–Brown–Rahman syndrome; while DNMT3B mutations are involved in immunodeficiency and intellectual disability syndromes such as immunodeficiency-centromeric instability-facial anomalies syndrome 1 (ICF 1).41