title: Andersen-Tawil syndrome: report of 3 novel mutations and high risk of symptomatic cardiac involvement.
abstract: BACKGROUND
  Andersen-Tawil syndrome (ATS) is a potassium channelopathy affecting cardiac and skeletal muscle. Periodic paralysis is a presenting symptom in some patients, whereas, in others, symptomatic arrhythmias or prolongation of QT in echocardiographic recordings will lead to diagnosis of ATS. Striking intrafamilial variability of expression of KCNJ2 mutations and rarity of the syndrome may lead to misdiagnosis.
  
  
  METHODS
  We report 15 patients from 8 Polish families with ATS, including 3 with novel KCNJ2 mutations.
  
  
  RESULTS
  All patients had dysmorphic features; periodic paralysis affected males more frequently than females (80% vs. 20%), and most attacks were normokalemic. Two patients (with T75M and T309I mutations) had aborted sudden cardiac death. An implantable cardioverter-defibrillator was utilized in 40% of cases.
  
  
  CONCLUSIONS
  KCNJ2 mutations cause a variable phenotype, with dysmorphic features seen in all patients studied, a high penetrance of periodic paralysis in males and ventricular arrhythmia with a risk of sudden cardiac death.
authors.affiliation: Department of Neurology, Medical University of Warsaw, Banacha 1a, 02 097, Warsaw, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Kostera-Pruszczyk
authors.forename: Anna
authors.initials: A
authors.lastname: Potulska-Chromik
authors.forename: Piotr
authors.initials: P
authors.lastname: Pruszczyk
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Bieganowska
authors.forename: Maria
authors.initials: M
authors.lastname: Miszczak-Knecht
authors.forename: Piotr
authors.initials: P
authors.lastname: Bienias
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Szczałuba
authors.forename: Hsien-Yang
authors.initials: HY
authors.lastname: Lee
authors.forename: Emily
authors.initials: E
authors.lastname: Quinn
authors.forename: Rafal
authors.initials: R
authors.lastname: Ploski
authors.forename: Anna
authors.initials: A
authors.lastname: Kaminska
authors.forename: Louis J
authors.initials: LJ
authors.lastname: Ptáček
mesh_terms: D000293:Adolescent; D000328:Adult; D050030:Andersen Syndrome / Q000150:complications* / Q000235:genetics* / Q000601:surgery; D002648:Child; D004252:DNA Mutational Analysis; D017147:Defibrillators, Implantable; D004452:Echocardiography; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006331:Heart Diseases / Q000209:etiology* / Q000235:genetics / Q000601:surgery; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009154:Mutation / Q000235:genetics*; D010245:Paralyses, Familial Periodic / Q000209:etiology / Q000235:genetics; D011044:Poland; D024661:Potassium Channels, Inwardly Rectifying / Q000235:genetics*; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: C489457:KCNJ2 protein, human; D024661:Potassium Channels, Inwardly Rectifying
keywords: KCNJ2; channelopathy; long QT; periodic paralysis; ventricular arrhythmia