Molecular Genetics Diversity of Primary Hemophagocytic Lymphohistiocytosis among Polish Pediatric Patients

AbstractHemophagocytic lymphohistiocytosis (HLH) is a clinical syndrome of life-threatening inflammation caused by an excessive, prolonged and ineffective immune response. An increasing number of HLH cases is recognized in Poland, but the genetic causes of familial HLH (FHL) have not been reported. We investigated the molecular genetics and associated outcomes of pediatric patients who met HLH criteria. We studied 54 patients with HLH, 36 of whom received genetic studies. Twenty-five patients were subjected to direct sequencing of thePRF1,UNC13D,STX11, XIAP andSH2D1A genes. Additionally, 11 patients were subjected to targeted next-generation sequencing. In our study group, 17 patients (31%) were diagnosed with primary HLH, with bi-allelic FHL variants identified in 13 (36%) patients whereas hemizygous changes were identified in 4 patients with X-linked lymphoproliferative diseases. In addition, one patient was diagnosed with X-linked immunodeficiency with magnesium defect, Epstein –Barr virus infection and neoplasia due to a hemizygousMAGT1 variant; another newborn was diagnosed with auto-inflammatory syndrome caused byMVK variants. The majority (65%) of FHL patients carriedUNC13D pathogenic variants, whereasPRF1 variants occurred in two patients. Novel variants inUNC13D,PRF1 andXIAP were detected. Epstein –Barr virus was the most common trigger noted in 23 (65%) of the patients with secondary HLH. In three patients with secondary HLH, heterozygous variants of FHL genes w...

Source: Archivum Immunologiae et Therapiae Experimentalis - October 22, 2021 Category: Allergy & Immunology Source Type: research