Familial Hemophagocytic Lymphohistiocytosis Type 5 Due To Novel STXB2 Gene Mutation: A Case Report

Familial Hemophagocytic lymphohistiocytosis (FHL) is a fatal autosomal recessive hyperinflammatory syndrome characterized by fever, hepatosplenomegaly, cytopenia, hyperferritenemia and widespread hemophagocytosis in the reticuloendothelial tissues. Diagnosis of FHL can be confirmed by the presence of typical clinical and laboratory features along with presence of a specific genetic mutation. Mutation in STXBP2 encoding syntaxin binding protein 2 (Munc 18 -2) is the newest described mutation that gives rise to FHL5. Here we present a case of FHL 5 with typical clinical and laboratory features of FHL and came out to be positive for homozygous missense variation in exon 3 of the STXBP2 gene (chr19:7703978; G>T).