title: Identification of KCNQ1 compound heterozygous mutations in three Chinese families with Jervell and Lange-Nielsen Syndrome.
abstract: CONCLUSIONS
  Besides expanding the spectrum of KCNQ1 mutations causing Jervell and Lange-Nielsen Syndrome (JLNS), the results showed diversity of its phenotypes, and emphasized the importance of molecular genetic analysis in confirming clinical diagnosis and making diagnosis possible before the emergency symptoms for deaf individuals.
  
  
  OBJECTIVE
  This study aimed to investigate four patients from three Chinese families with congenital hearing loss clinically and genetically.
  
  
  METHODS
  Genetic analysis of previously reported deafness genes based on massively parallel sequencing was conducted in more than five thousand Chinese hearing loss patients. Detailed clinical features of the patients with compound heterozygous or homozygous mutations of KCNQ1 gene were collected and analyzed.
  
  
  RESULTS
  Compound mutations of KCNQ1 were found to be the genetic etiology of four patients from three families. Among the six KCNQ1 mutations, c.546C > A was identified as a novel mutation, c.965C > T had been reported in JLNS, while c.683 + 5G > A, c.1484_1485delCT, c.905C > T and c.1831G > A were previously reported in LQT1. In addition to congenital profound hearing loss in all subjects, two sibling subjects showed typical JLNS cardiac phenotype of prolonged QTc and recurrent syncopal episodes. One subject presented not only JLNS, but also iron-deficiency anemia and epilepsy. The other subject did not present any cardiac phenotype.
authors.affiliation: a Institute of Otolaryngology , Chinese PLA General Hospital , Beijing , PR China.|b School of Medicine , Nankai University , Tianjin , PR China.
authors.forename: Cuicui
authors.initials: C
authors.lastname: Wang
authors.affiliation: c Medical Genetics Center , Southwest Hospital, Third Military Medical University , Chongqing , PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Lu
authors.affiliation: c Medical Genetics Center , Southwest Hospital, Third Military Medical University , Chongqing , PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Cheng
authors.affiliation: c Medical Genetics Center , Southwest Hospital, Third Military Medical University , Chongqing , PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: d Department of Otolaryngology , Ordos Central Hospital , Ordos , Inner Mongolia Province , PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: c Medical Genetics Center , Southwest Hospital, Third Military Medical University , Chongqing , PR China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Peng
authors.affiliation: a Institute of Otolaryngology , Chinese PLA General Hospital , Beijing , PR China.
authors.forename: Di
authors.initials: D
authors.lastname: Zhang
authors.affiliation: a Institute of Otolaryngology , Chinese PLA General Hospital , Beijing , PR China.
authors.forename: Hong
authors.initials: H
authors.lastname: Duan
authors.affiliation: a Institute of Otolaryngology , Chinese PLA General Hospital , Beijing , PR China.
authors.forename: Dongyi
authors.initials: D
authors.lastname: Han
authors.affiliation: a Institute of Otolaryngology , Chinese PLA General Hospital , Beijing , PR China.|c Medical Genetics Center , Southwest Hospital, Third Military Medical University , Chongqing , PR China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Yuan
mesh_terms: D000818:Animals; D044466:Asian People / Q000235:genetics; D002648:Child; D002681:China; D004252:DNA Mutational Analysis; D004569:Electroencephalography; D005260:Female; D006579:Heterozygote; D006801:Humans; D029593:Jervell-Lange Nielsen Syndrome / Q000235:genetics*; D051657:KCNQ1 Potassium Channel / Q000235:genetics*; D008297:Male; D009154:Mutation
chemical_list: D051657:KCNQ1 Potassium Channel; C496909:KCNQ1 protein, human
keywords: JLNS; KCNQ1; genetic etiology; mutation