title: [An analysis of etiological and genetic factors of a patient with familial hemophagocytic lymphohistiocytosis].
abstract: OBJECTIVE
  To analyze the etiological factor and genetic feature of a familial hemophagocytic lymphohistiocytosis patient with PRF1 mutation (FHL2) with human herpesvirus 7 (HHV7) infection and its family constellation.
  
  
  METHODS
  Clinical characteristics, laboratory examinations of a FHL2 case with HHV7 infection were reported. HHV1-HHV8 virus DNA was screened by PCR; NK cell function was analyzed by flow cytometry; PRF1 gene mutations were analyzed by PCR and direct sequencing, structure of mutant PRF1 proteins were analyzed using ExPasy and I-TASSER server and genetics pedigree were analyzed.
  
  
  RESULTS
  The patient's HHV7 viral was detected positive with DNA copy number of 350/10(6) peripheral nucleated cells. Flow cytometry analysis showed decrease both in proportion of perforin positive NK cells and perforin protein expression. Genetic testing showed PRF1 biallelic heterozygote mutations (c.503G > A/p.S168N and c.1177T > C/p.C393R) and pedigree analysis showed they were inherited. The patient was then treated with antivirus therapy, dexamethasone and VP16 therapy, but only achieved partial response. The patient was then followed by human leukocyte antigen 10/10 allele identical non-consanguinity allogeneic hematopoietic stem cell transplantations (allo-HSCT) and soon the successful implantation of donor hematopoietic cells and persistent recovery was achieved. The patient was now surviving without recurrence for 9 months after allo-HSCT.
  
  
  CONCLUSIONS
  FHL is prone to be misdiagnosed as lymphoma. Genetic analysis of related gene mutation and herpes simplex virus detection will help in early and accurate diagnosis. Allo-HSCT is a fundamental treatment of FHL.
authors.affiliation: Beijing Daopei Hospital, Beijing 100049, China.
authors.forename: Hong-Xing
authors.initials: HX
authors.lastname: Liu
authors.forename: Chun-Rong
authors.initials: CR
authors.lastname: Tong
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Juan
authors.initials: J
authors.lastname: Zhu
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Peng
authors.initials: P
authors.lastname: Cai
authors.forename: Wen
authors.initials: W
authors.lastname: Teng
authors.forename: Jun-Fang
authors.initials: JF
authors.lastname: Yang
authors.forename: Ya-Li
authors.initials: YL
authors.lastname: Zhang
authors.forename: Dao-Pei
authors.initials: DP
authors.lastname: Lu
mesh_terms: D000293:Adolescent; D004252:DNA Mutational Analysis; D004279:DNA, Viral / Q000097:blood; D005260:Female; D016199:Herpesvirus 7, Human; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology; D051359:Lymphohistiocytosis, Hemophagocytic / Q000235:genetics* / Q000601:surgery / Q000821:virology*; D010375:Pedigree; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins / Q000235:genetics; D019349:Roseolovirus Infections / Q000150:complications*; D033581:Stem Cell Transplantation
chemical_list: D004279:DNA, Viral; C510468:PRF1 protein, human; D052899:Pore Forming Cytotoxic Proteins; D054353:Perforin