title: Early-onset stroke and vasculopathy associated with mutations in ADA2.
abstract: BACKGROUND
  We observed a syndrome of intermittent fevers, early-onset lacunar strokes and other neurovascular manifestations, livedoid rash, hepatosplenomegaly, and systemic vasculopathy in three unrelated patients. We suspected a genetic cause because the disorder presented in early childhood.
  
  
  METHODS
  We performed whole-exome sequencing in the initial three patients and their unaffected parents and candidate-gene sequencing in three patients with a similar phenotype, as well as two young siblings with polyarteritis nodosa and one patient with small-vessel vasculitis. Enzyme assays, immunoblotting, immunohistochemical testing, flow cytometry, and cytokine profiling were performed on samples from the patients. To study protein function, we used morpholino-mediated knockdowns in zebrafish and short hairpin RNA knockdowns in U937 cells cultured with human dermal endothelial cells.
  
  
  RESULTS
  All nine patients carried recessively inherited mutations in CECR1 (cat eye syndrome chromosome region, candidate 1), encoding adenosine deaminase 2 (ADA2), that were predicted to be deleterious; these mutations were rare or absent in healthy controls. Six patients were compound heterozygous for eight CECR1 mutations, whereas the three patients with polyarteritis nodosa or small-vessel vasculitis were homozygous for the p.Gly47Arg mutation. Patients had a marked reduction in the levels of ADA2 and ADA2-specific enzyme activity in the blood. Skin, liver, and brain biopsies revealed vasculopathic changes characterized by compromised endothelial integrity, endothelial cellular activation, and inflammation. Knockdown of a zebrafish ADA2 homologue caused intracranial hemorrhages and neutropenia - phenotypes that were prevented by coinjection with nonmutated (but not with mutated) human CECR1. Monocytes from patients induced damage in cocultured endothelial-cell layers.
  
  
  CONCLUSIONS
  Loss-of-function mutations in CECR1 were associated with a spectrum of vascular and inflammatory phenotypes, ranging from early-onset recurrent stroke to systemic vasculopathy or vasculitis. (Funded by the National Institutes of Health Intramural Research Programs and others.).
authors.affiliation: The authors' affiliations are listed in the Appendix.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhou
authors.forename: Dan
authors.initials: D
authors.lastname: Yang
authors.forename: Amanda K
authors.initials: AK
authors.lastname: Ombrello
authors.forename: Andrey V
authors.initials: AV
authors.lastname: Zavialov
authors.forename: Camilo
authors.initials: C
authors.lastname: Toro
authors.forename: Anton V
authors.initials: AV
authors.lastname: Zavialov
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Stone
authors.forename: Jae Jin
authors.initials: JJ
authors.lastname: Chae
authors.forename: Sergio D
authors.initials: SD
authors.lastname: Rosenzweig
authors.forename: Kevin
authors.initials: K
authors.lastname: Bishop
authors.forename: Karyl S
authors.initials: KS
authors.lastname: Barron
authors.forename: Hye Sun
authors.initials: HS
authors.lastname: Kuehn
authors.forename: Patrycja
authors.initials: P
authors.lastname: Hoffmann
authors.forename: Alejandra
authors.initials: A
authors.lastname: Negro
authors.forename: Wanxia L
authors.initials: WL
authors.lastname: Tsai
authors.forename: Edward W
authors.initials: EW
authors.lastname: Cowen
authors.forename: Wuhong
authors.initials: W
authors.lastname: Pei
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Milner
authors.forename: Christopher
authors.initials: C
authors.lastname: Silvin
authors.forename: Theo
authors.initials: T
authors.lastname: Heller
authors.forename: David T
authors.initials: DT
authors.lastname: Chin
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Patronas
authors.forename: John S
authors.initials: JS
authors.lastname: Barber
authors.forename: Chyi-Chia R
authors.initials: CC
authors.lastname: Lee
authors.forename: Geryl M
authors.initials: GM
authors.lastname: Wood
authors.forename: Alexander
authors.initials: A
authors.lastname: Ling
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Kelly
authors.forename: David E
authors.initials: DE
authors.lastname: Kleiner
authors.forename: James C
authors.initials: JC
authors.lastname: Mullikin
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Ganson
authors.forename: Heidi H
authors.initials: HH
authors.lastname: Kong
authors.forename: Sophie
authors.initials: S
authors.lastname: Hambleton
authors.forename: Fabio
authors.initials: F
authors.lastname: Candotti
authors.forename: Martha M
authors.initials: MM
authors.lastname: Quezado
authors.forename: Katherine R
authors.initials: KR
authors.lastname: Calvo
authors.forename: Hawwa
authors.initials: H
authors.lastname: Alao
authors.forename: Beverly K
authors.initials: BK
authors.lastname: Barham
authors.forename: Anne
authors.initials: A
authors.lastname: Jones
authors.forename: James F
authors.initials: JF
authors.lastname: Meschia
authors.forename: Bradford B
authors.initials: BB
authors.lastname: Worrall
authors.forename: Scott E
authors.initials: SE
authors.lastname: Kasner
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Rich
authors.forename: Raphaela
authors.initials: R
authors.lastname: Goldbach-Mansky
authors.forename: Mario
authors.initials: M
authors.lastname: Abinun
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Chalom
authors.forename: Alisa C
authors.initials: AC
authors.lastname: Gotte
authors.forename: Marilynn
authors.initials: M
authors.lastname: Punaro
authors.forename: Virginia
authors.initials: V
authors.lastname: Pascual
authors.forename: James W
authors.initials: JW
authors.lastname: Verbsky
authors.forename: Troy R
authors.initials: TR
authors.lastname: Torgerson
authors.forename: Nora G
authors.initials: NG
authors.lastname: Singer
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Gershon
authors.forename: Seza
authors.initials: S
authors.lastname: Ozen
authors.forename: Omer
authors.initials: O
authors.lastname: Karadag
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Fleisher
authors.forename: Elaine F
authors.initials: EF
authors.lastname: Remmers
authors.forename: Shawn M
authors.initials: SM
authors.lastname: Burgess
authors.forename: Susan L
authors.initials: SL
authors.lastname: Moir
authors.forename: Massimo
authors.initials: M
authors.lastname: Gadina
authors.forename: Raman
authors.initials: R
authors.lastname: Sood
authors.forename: Michael S
authors.initials: MS
authors.lastname: Hershfield
authors.forename: Manfred
authors.initials: M
authors.lastname: Boehm
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Kastner
authors.forename: Ivona
authors.initials: I
authors.lastname: Aksentijevich
mesh_terms: D000243:Adenosine Deaminase / Q000172:deficiency* / Q000235:genetics*; D017668:Age of Onset; D000818:Animals; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000473:pathology; D005260:Female; D005334:Fever / Q000235:genetics; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000172:deficiency* / Q000235:genetics*; D008297:Male; D009154:Mutation; D010375:Pedigree; D010488:Polyarteritis Nodosa / Q000235:genetics; D017422:Sequence Analysis, DNA; D012867:Skin / Q000473:pathology; D020521:Stroke / Q000235:genetics*; D014652:Vascular Diseases / Q000235:genetics*; D014657:Vasculitis / Q000235:genetics / Q000473:pathology; D015027:Zebrafish
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; C408373:ADA2 protein, human; D000243:Adenosine Deaminase