Data showed the heterozygous variant of UNC13D c.2588G>A might act as a genetic risk factor predisposing carriers to conditions like HLH, lymphoma, etc. This study underscores the pathogenic role of the UNC13D c.2588G>A variant and expands our understanding of the genetic basis of adult-onset HLH. This evidence concerns the gene UNC13D and hemophagocytic syndrome.