Whole‐exome sequencing showed genetic defects of familial hemophagocytic lymphohistiocytosis (FHL) with two heterozygous mutations of p.V61A missense mutation (c.182T>C) and p.T450M missense mutation (c.1349C>T) in the coding sequence of the PRF1 gene. Here, PRF1 is linked to hemophagocytic syndrome.