Transethnic Genome-Wide Association Study Provides Insights in the Genetic Architecture and Heritability of Long QT Syndrome.

Background: Long QT syndrome (LQTS) is a rare genetic disorder and a major preventable cause of sudden cardiac death in the young. A causal rare genetic variant with large effect size is identified in up to 80% of probands (genotype positive) and cascade family screening shows incomplete penetrance of genetic variants. Furthermore, a proportion of cases meeting diagnostic criteria for LQTS remain genetically elusive despite genetic testing of established genes (genotype negative).

Autonomic Function and QT Interval During Night-Time Sleep in Infant Long QT Syndrome.

Background: Sudden infant death syndrome mainly occurs during night-time sleep. Approximately 10% of cases are thought to involve infants with long QT syndrome (LQTS). Autonomic function and QT interval in night-time sleep in early infancy in LQTS infants, however, remain controversial.

Probability of diagnosing long QT syndrome in children and adolescents according to the criteria of the HRS/EHRA/APHRS expert consensus statement.

Aims: The present study aimed to determine the probability of diagnosing long QT syndrome (LQTS) in children and adolescents based on the HRS/EHRA/APHRS criteria for LQTS. We used data of a school-based electrocardiographic screening programme in Japan.

Methods And Results: The total numbers of subjects who participated in the screening programme between 2008 and 2013 in Kagoshima, Japan, were 33 051 first- and 34 751 seventh-grade students, aged 6 and 12 years, respectively.

Genetic characteristics of children and adolescents with long-QT syndrome diagnosed by school-based electrocardiographic screening programs.

Background: A school-based electrocardiographic screening program has been developed in Japan. However, few data are available on the genetic characteristics of pediatric patients with long-QT syndrome who were diagnosed by this program.

Methods And Results: A total of 117 unrelated probands aged ≤18 years were the subjects who were referred to our centers for genetic testing.

Risk factors for symptoms in long QT syndrome patients in a single pediatric center.

Background: Long QT syndrome (LQTS) is a leading cause of sudden cardiac death due to arrhythmia in the pediatric population. This study aimed to determine risk factors for the presence of LQTS-related symptoms in a single pediatric center.

Methods: Subjects were 146 consecutive LQTS patients (M:F = 72:74) who visited our hospital between April 2005 and August 2012 and during the preceding 24 months.