Two siblings with immunodeficiency, facial abnormalities and chromosomal instability without mutation in DNMT3B gene but liability towards malignancy; a new chromatin disorder delineation?

Background ICF syndrome (standing for Immunodeficiency, Centromere instability and Facial anomalies syndrome) is a very rare autosomal recessive immune disorder caused by mutations of the gene de novo DNA-methyltransferase 3B (DNMT3B). However, in the literature similar clinical cases without such mutations are reported, as well.