These cases included a male patient with CAEBV carrying <i>SH2D1A</i> hypomorphic mutation (c.7G > T, p.Ala3Ser) and two male patients with CAEBV/EBV-HLH carrying the <i>XIAP</i> hypomorphic variant (c.1045_1047delGAG, p.Glu349del), along with another female patient with CAEBV carrying the same <i>XIAP</i> variant. This evidence concerns the gene XIAP and hemophagocytic syndrome.