title: Brief Report: Cryopyrin-Associated Periodic Syndrome Caused by a Myeloid-Restricted Somatic NLRP3 Mutation.
abstract: OBJECTIVE
  To identify the cause of disease in an adult patient presenting with recent-onset fevers, chills, urticaria, fatigue, and profound myalgia, who was found to be negative for cryopyrin-associated periodic syndrome (CAPS) NLRP3 mutations by conventional Sanger DNA sequencing.
  
  
  METHODS
  We performed whole-exome sequencing and targeted deep sequencing using DNA from the patient's whole blood to identify a possible NLRP3 somatic mutation. We then screened for this mutation in subcloned NLRP3 amplicons from fibroblasts, buccal cells, granulocytes, negatively selected monocytes, and T and B lymphocytes and further confirmed the somatic mutation by targeted sequencing of exon 3.
  
  
  RESULTS
  We identified a previously reported CAPS-associated mutation, p.Tyr570Cys, with a mutant allele frequency of 15% based on exome data. Targeted sequencing and subcloning of NLRP3 amplicons confirmed the presence of the somatic mutation in whole blood at a ratio similar to the exome data. The mutant allele frequency was in the range of 13.3-16.8% in monocytes and 15.2-18% in granulocytes. Notably, this mutation was either absent or present at a very low frequency in B and T lymphocytes, in buccal cells, and in the patient's cultured fibroblasts.
  
  
  CONCLUSIONS
  Our findings indicate the possibility of myeloid-restricted somatic mosaicism in the pathogenesis of CAPS, underscoring the emerging role of massively parallel sequencing in clinical diagnosis.
authors.affiliation: National Human Genome Research Institute, NIH, Bethesda, Maryland.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: National Human Genome Research Institute, NIH, Bethesda, Maryland.
authors.forename: Ivona
authors.initials: I
authors.lastname: Aksentijevich
authors.affiliation: National Human Genome Research Institute, NIH, Bethesda, Maryland.
authors.forename: Geryl M
authors.initials: GM
authors.lastname: Wood
authors.affiliation: National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland.
authors.forename: Avram D
authors.initials: AD
authors.lastname: Walts
authors.affiliation: National Human Genome Research Institute, NIH, Bethesda, Maryland.
authors.forename: Patrycja
authors.initials: P
authors.lastname: Hoffmann
authors.affiliation: National Human Genome Research Institute, NIH, Bethesda, Maryland.
authors.forename: Elaine F
authors.initials: EF
authors.lastname: Remmers
authors.affiliation: National Human Genome Research Institute, NIH, Bethesda, Maryland.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Kastner
authors.affiliation: National Human Genome Research Institute, NIH, Bethesda, Maryland.
authors.forename: Amanda K
authors.initials: AK
authors.lastname: Ombrello
mesh_terms: D001402:B-Lymphocytes / Q000166:cytology / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics*; D056587:Cryopyrin-Associated Periodic Syndromes / Q000235:genetics*; D059472:Exome / Q000235:genetics; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D006098:Granulocytes / Q000166:cytology / Q000378:metabolism; D006801:Humans; D008875:Middle Aged; D009000:Monocytes / Q000166:cytology / Q000378:metabolism; D009061:Mouth Mucosa / Q000166:cytology / Q000378:metabolism; D009154:Mutation; D022423:Myeloid Cells / Q000166:cytology / Q000378:metabolism*; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; D017422:Sequence Analysis, DNA; D013601:T-Lymphocytes / Q000166:cytology / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; C453881:NLRP3 protein, human