Definition

Pathogenic variants in the KCNH2 (HERG) gene (7q36.1) impair the rapid delayed rectifier potassium channel current (IKr) involved in cardiac repolarization, leading to QT interval prolongation, syncope, torsades de pointes-type ventricular tachycardia, and risk of sudden cardiac death. LQT2 accounts for about 25 to 30 percent of all congenital long QT syndrome cases.

Gene/region examined

KCNH2 - Whole Gene

Method

Sequence analysis

Accepted sample types

EDTA blood, AF, CVS

Inheritance

Inherited, autosomal dominant (Romano-Ward syndrome).

Related Tests

Inheritance Patterns

Describes how a genetic condition is passed on within a family. There are five main patterns

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Carrier (Heterozygous / Homozygous)

Why it matters: In autosomal recessive inheritance, when each parent is a carrier (while both appear healthy), the chance of their child being born with the disease is 25% in each

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VUS (Variant of Uncertain Significance)

This is the situation where the test has detected a change in the DNA, but the role of this change in the development of disease is unconfirmed.

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How to Read a Genetic Test Result (Positive / Negative / VUS)

A genetic test result falls into three main categories

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Types of Genetic Tests

A genetic test is a type of medical test that detects changes in genes, chromosomes or proteins. Today there are more than 77,000 genetic tests available.

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