NSD2 and Wolf-Hirschhorn syndrome: As previously mentioned, the hemizygous loss of NSD2 is related par excellence to the Wolf–Hirschhorn Syndrome (WHS), where a variable segment of chromosome 4 is lost, including the WHSC1-containing region [65,70]; WHS is a rare disease, with a prevalence of 1:20,000/50,000 worldwide, which affects the whole organism causing severe developmental defects, including failures in antibody production and other lymphocyte functions [110].