Remission and relapse of hemophagocytic lymphohistiocytosis in a patient harboring a PRF1 homozygous mutation: a case report.

The aim of this paper was to describe a case of familial hemophagocytic lymphohistiocytosis (HLH) in a pediatric patient with a PRF1 homozygous mutation. An 8-year-old boy diagnosed with HLH was in remission after undergoing nonspecific treatment; however, merely 2 months later, he was presented at our hospital with a relapse of HLH. His genetic analysis showed that he had a homozygous mutation c.1066C>T in the PRF1 gene. Timely distinction of primary HLH from secondary HLH is critical.