The patient was also a heterozygous carrier of a hypomorphic, low-frequency variant in PRF1 (p.A91V, MAF = 0.0293), which has been described as a risk factor for late-onset hemophagocytic lymphohistiocytosis, acquired aplastic anemia, and different T cell lymphoid neoplasms (27, 28). This evidence concerns the gene PRF1 and hemophagocytic syndrome.