A cardiac arrhythmia syndrome caused by loss of ankyrin-B function.

Published

Journal Article

220-kDa ankyrin-B is required for coordinated assembly of Na/Ca exchanger, Na/K ATPase, and inositol trisphosphate (InsP(3)) receptor at transverse-tubule/sarcoplasmic reticulum sites in cardiomyocytes. A loss-of-function mutation of ankyrin-B identified in an extended kindred causes a dominantly inherited cardiac arrhythmia, initially described as type 4 long QT syndrome. Here we report the identification of eight unrelated probands harboring ankyrin-B loss-of-function mutations, including four previously undescribed mutations, whose clinical features distinguish the cardiac phenotype associated with loss of ankyrin-B activity from classic long QT syndromes. Humans with ankyrin-B mutations display varying degrees of cardiac dysfunction including bradycardia, sinus arrhythmia, idiopathic ventricular fibrillation, catecholaminergic polymorphic ventricular tachycardia, and risk of sudden death. However, a prolonged rate-corrected QT interval was not a consistent feature, indicating that ankyrin-B dysfunction represents a clinical entity distinct from classic long QT syndromes. The mutations are localized in the ankyrin-B regulatory domain, which distinguishes function of ankyrin-B from ankyrin-G in cardiomyocytes. All mutations abolish ability of ankyrin-B to restore abnormal Ca(2+) dynamics and abnormal localization and expression of Na/Ca exchanger, Na/K ATPase, and InsP(3)R in ankyrin-B(+/-) cardiomyocytes. This study, considered together with the first description of ankyrin-B mutation associated with cardiac dysfunction, supports a previously undescribed paradigm for human disease due to abnormal coordination of multiple functionally related ion channels and transporters, in this case the Na/K ATPase, Na/Ca exchanger, and InsP(3) receptor.

Full Text

Duke Authors

Cited Authors

  • Mohler, PJ; Splawski, I; Napolitano, C; Bottelli, G; Sharpe, L; Timothy, K; Priori, SG; Keating, MT; Bennett, V

Published Date

  • June 15, 2004

Published In

Volume / Issue

  • 101 / 24

Start / End Page

  • 9137 - 9142

PubMed ID

  • 15178757

Pubmed Central ID

  • 15178757

International Standard Serial Number (ISSN)

  • 0027-8424

Digital Object Identifier (DOI)

  • 10.1073/pnas.0402546101

Language

  • eng

Conference Location

  • United States