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Cardiac Channelopathies Associated with Infantile Fatal Ventricular Arrhythmias: From the Cradle to the Bench
Author(s) -
KATO KOICHI,
MAKIYAMA TAKERU,
WU JIE,
DING WEIGUANG,
KIMURA HIROMI,
NAIKI NOBU,
OHNO SEIKO,
ITOH HIDEKI,
NAKANISHI TOSHIO,
MATSUURA HIROSHI,
HORIE MINORU
Publication year - 2014
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/jce.12270
Subject(s) - medicine , chinese hamster ovary cell , mutation , ventricular fibrillation , sudden cardiac death , cardiology , cardiac arrhythmia , atrial fibrillation , genetics , biology , gene , receptor
Channelopathies in Infantile Arrhythmias Background Fatal ventricular arrhythmias in the early period of life have been associated with cardiac channelopathies for decades, and postmortem analyses in SIDS victims have provided evidence of this association. However, the prevalence and functional properties of cardiac ion channel mutations in infantile fatal arrhythmia cases are not clear. Methods and Results Seven infants with potentially lethal arrhythmias at age < 1 year (5 males, age of onset 44.1 ± 72.1 days) were genetically analyzed for KCNQ1, KCNH2, KCNE1–5, KCNJ2, SCN5A , GJA5 , and CALM1 by using denaturing high‐performance liquid chromatography and direct sequencing. Whole‐cell currents of wildtype and mutant channels were recorded and analyzed in Chinese hamster ovary cells transfected with SCN5A and KCNH2 cDNA. In 5 of 7 patients, we identified 4 mutations (p.N1774D, p.T290fsX53, p.F1486del and p.N406K) in SCN5A , and 1 mutation (p.G628D) in KCNH2 . N1774D, F1486del, and N406K in SCN5A displayed tetrodotoxin‐sensitive persistent late Na + currents. By contrast, SCN5A ‐T290fsX53 was nonfunctional. KCNH2 ‐G628D exhibited loss of channel function. Conclusion Genetic screening of 7 patients was used to demonstrate the high prevalence of cardiac channelopathies. Functional assays revealed both gain and loss of channel function in SCN5A mutations, as well as loss of function associated with the KCNH2 mutation.