Notably, patients with hypomorphic mutation of POLE, in FILS and IMAGe syndromes, and POLE2 exhibit a characteristic reduction in the number of B lymphocytes and variable degrees of immunodeficiency (Pachlopnik Schmid et al., 2012; Logan et al., 2018; Frugoni et al., 2016). This evidence concerns the gene POLE2 and Immunodeficiency.