Given (i) the absence in the patient 2 of clinical signs of the immunodeficiency-centromeric instability-facial anomalies syndrome 1 (OMIM 242,860) associated with deleterious DNMT3B SNVs, and (ii) the high predicted variability associated with this SNV in the various databases (Table 1), we decided to screen the entire exome and to focus on genes that are strongly expressed in the testis. Here, DNMT3B is linked to immunodeficiency disease.