Genetic testing revealed two missense variants associated with HLH: c.2131G>A (p.Glu711Lys) in Exon13 of the RECQL4 gene, with a heterozygous variant frequency of 42.78 %, and c.3107C>T (p.Glu1036Ala) in Exon6 of the LYST gene, with a heterozygous variant frequency of 47.72 %. This evidence concerns the gene LYST and hemophagocytic syndrome.