title: Screening of KCNN3 in patients with early-onset lone atrial fibrillation.
abstract: OBJECTIVE
  The aim of this study was to screen KCNN3 encoding the small-conductance calcium-activated K+ channel (SK3) in lone atrial fibrillation patients. Atrial fibrillation (AF) is the most common cardiac arrhythmia. A genome-wide association study has recently associated an intronic single-nucleotide polymorphism (SNP) in KCNN3 with lone AF.
  
  
  RESULTS
  We sequenced the coding region and splice junctions of KCNN3 in 209 early-onset lone AF patients, screening for variations. A group of 208 healthy blood donors with normal ECGs and without cardiac symptoms were used as controls. All patients and controls were of Danish ethnicity. No mutations were found in the coding regions or splice sites of KCNN3. We found one known exonic synonymous SNP (rs1131820) in KCNN3 that was associated with AF. Both the genotype distribution and allele frequencies of SNP rs1131820 were significantly different between the AF cases and controls (PGenotype=0.047 and PAllele=0.027). Being a homozygous carrier of the major allele (GG) vs. the minor allele (AA) of rs1131820 was associated with an odds ratio of 2.85 (95% CI 1.13-7.18, P=0.026) for lone AF.
  
  
  CONCLUSIONS
  In this study of 209 young lone AF patients, we found no mutations in the exons or splice sites of KCNN3, but we found an association between the synonymous SNP rs1131820 in KCNN3 and lone AF.
authors.affiliation: The Danish National Research Foundation Centre for Cardiac Arrhythmia (DARC), University of Copenhagen, Copenhagen, Denmark.
authors.forename: Morten S
authors.initials: MS
authors.lastname: Olesen
authors.forename: Javad
authors.initials: J
authors.lastname: Jabbari
authors.forename: Anders G
authors.initials: AG
authors.lastname: Holst
authors.forename: Jonas B
authors.initials: JB
authors.lastname: Nielsen
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Steinbrüchel
authors.forename: Thomas
authors.initials: T
authors.lastname: Jespersen
authors.forename: Stig
authors.initials: S
authors.lastname: Haunsø
authors.forename: Jesper H
authors.initials: JH
authors.lastname: Svendsen
mesh_terms: D000328:Adult; D017668:Age of Onset; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics*; D016022:Case-Control Studies; D015331:Cohort Studies; D003718:Denmark; D004562:Electrocardiography; D005091:Exons / Q000235:genetics; D005260:Female; D005820:Genetic Testing; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D051640:Small-Conductance Calcium-Activated Potassium Channels / Q000235:genetics*
chemical_list: C406328:KCNN3 protein, human; D051640:Small-Conductance Calcium-Activated Potassium Channels