title: Genetic background of catecholaminergic polymorphic ventricular tachycardia in Japan.
abstract: BACKGROUND
  The genetic background of catecholaminergic polymorphic ventricular tachycardia (CPVT) has been extensively investigated for the last decade in Western countries, but it remains unstudied in the Asian population.
  
  
  RESULTS
  In 50 Japanese probands from unrelated families who satisfied clinical criteria for CPVT, genetic testing was conducted in all exons on 3 CPVT-related genes: cardiac ryanodine receptor 2 (RYR2), calsequestrin 2 (CASQ2) and inward rectifier potassium channel 2 (KCNJ2), and the clinical features between RYR2-genotyped and -non-genotyped patient groups were compared. Genetic and clinical evaluation was also done in 46 family members. In the genetic screening, 28 (18 novel) RYR2 (56.0%), 1 compound heterozygous CASQ2 (2.0%) and 1 KCNJ2 (2.0%) mutation carriers were identified. In the RYR2 mutation-positive group, the frequency of bidirectional ventricular tachycardia and the use of β-blockers were significantly higher than in the mutation-negative group. In contrast, there was no significant difference in supraventricular arrhythmias between the 2 groups. With regard to disease penetrance, the number of family members of RYR2-genotyped probands with a clinical diagnosis of CPVT was high.
  
  
  CONCLUSIONS
  Thirty gene mutation carriers were found for 3 genes in 50 probands clinically diagnosed as having CPVT. The penetrance of CPVT phenotype was significantly higher in RYR2 mutation carriers, thus RYR2 gene screening in CPVT patients would be indispensable to prevent unexpected cardiac sudden death of young family members.
authors.affiliation: Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan.
authors.forename: Mihoko
authors.initials: M
authors.lastname: Kawamura
authors.forename: Seiko
authors.initials: S
authors.lastname: Ohno
authors.forename: Nobu
authors.initials: N
authors.lastname: Naiki
authors.forename: Iori
authors.initials: I
authors.lastname: Nagaoka
authors.forename: Kenichi
authors.initials: K
authors.lastname: Dochi
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.forename: Kanae
authors.initials: K
authors.lastname: Hasegawa
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kimura
authors.forename: Akashi
authors.initials: A
authors.lastname: Miyamoto
authors.forename: Yuka
authors.initials: Y
authors.lastname: Mizusawa
authors.forename: Hideki
authors.initials: H
authors.lastname: Itoh
authors.forename: Takeru
authors.initials: T
authors.lastname: Makiyama
authors.forename: Naokata
authors.initials: N
authors.lastname: Sumitomo
authors.forename: Hiroya
authors.initials: H
authors.lastname: Ushinohama
authors.forename: Kotaro
authors.initials: K
authors.lastname: Oyama
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Murakoshi
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Aonuma
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Horigome
authors.forename: Takafumi
authors.initials: T
authors.lastname: Honda
authors.forename: Masao
authors.initials: M
authors.lastname: Yoshinaga
authors.forename: Makoto
authors.initials: M
authors.lastname: Ito
authors.forename: Minoru
authors.initials: M
authors.lastname: Horie
mesh_terms: D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage; D044466:Asian People; D002155:Calsequestrin / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005091:Exons; D005190:Family; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D009154:Mutation; D019683:Penetrance; D024661:Potassium Channels, Inwardly Rectifying / Q000235:genetics*; D019837:Ryanodine Receptor Calcium Release Channel / Q000235:genetics*; D017180:Tachycardia, Ventricular / Q000188:drug therapy / Q000235:genetics*; D000098850:Polymorphic Catecholaminergic Ventricular Tachycardia
chemical_list: D000319:Adrenergic beta-Antagonists; C443109:CASQ2 protein, human; D002155:Calsequestrin; C489457:KCNJ2 protein, human; D024661:Potassium Channels, Inwardly Rectifying; D019837:Ryanodine Receptor Calcium Release Channel