title: [Heterozygous mutation in KCNQ1 cause Jervell and Lange-Nielsen syndrome].
abstract: OBJECTIVE
  Jervell and Lange-Nielsen syndrome (JLNS) is a severe cardioauditory syndrome manifested as QT interval prolongation, abnormal T waves, and relative bradycardia ventricular tachyarrhythmias. In this report, we screened a nonconsanguineous families with JLNS for mutations in KCNQ1.
  
  
  METHODS
  Mutation analysis was performed by using purified PCR products to direct sequence analysis on an ABI-3730XL automated DNA sequencer. The whole sequence of proband' KCNQ1 was screened firstly, then screened the mutation exon sequences of others of the family and 50 unrelated normal persons.
  
  
  RESULTS
  A heterogeneous mutation was identified in the patients of the JLNS family, a missense mutation (G-->T) at nucleotide 917 encoded in exon 6 of KCNQ1. This substitution leads to a change from glycine to Valine at codon 306(G306V) corresponding to the S5 transmembrane segment of KCNQ1. The other normal members of the family and 50 unrelated normal persons were not identified this mutation.
  
  
  CONCLUSIONS
  The result suggested that not only homozygous mutations or compound heterozygous mutations in KCNQ1 could cause Jervell-Lange-Nielsen syndrome, the single heterozygous mutation may also cause Jervell-Lange-Nielsen syndrome.
authors.affiliation: Department of Cardiology, People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Wen-ling
authors.initials: WL
authors.lastname: Liu
authors.forename: Da-yi
authors.initials: DY
authors.lastname: Hu
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.forename: Cui-lan
authors.initials: CL
authors.lastname: Li
authors.forename: Xu-guang
authors.initials: XG
authors.lastname: Qin
authors.forename: Yun-tian
authors.initials: YT
authors.lastname: Li
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.forename: Zhi-ming
authors.initials: ZM
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Dong
authors.forename: Yu
authors.initials: Y
authors.lastname: Qi
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D005838:Genotype; D006801:Humans; D029593:Jervell-Lange Nielsen Syndrome / Q000235:genetics*; D051657:KCNQ1 Potassium Channel / Q000235:genetics*; D008133:Long QT Syndrome / Q000235:genetics; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense; D010375:Pedigree; D055815:Young Adult
chemical_list: D051657:KCNQ1 Potassium Channel; C496909:KCNQ1 protein, human