GENE REFERENCE / HGNC:6251

KCNH2

potassium voltage-gated channel subfamily H member 2

protein-coding gene7q36.1Gene information

What does this gene do?

The KCNH2 gene belongs to a large family of genes that provide instructions for making potassium channels. These channels, which transport positively charged atoms (ions) of potassium out of cells, play key roles in a cell's ability to generate and transmit electrical signals.

The specific function of a potassium channel depends on its protein components and its location in the body. Channels made with KCNH2 proteins (also known as hERG1) are active in heart (cardiac) muscle. They are involved in recharging the cardiac muscle after each heartbeat to maintain a regular rhythm. The KCNH2 protein is also produced in nerve cells and certain immune cells (microglia) in the brain and spinal cord (central nervous system).

The proteins produced from the KCNH2 gene and another gene, KCNE2, interact to form a functional potassium channel. Four alpha subunits, each produced from the KCNH2 gene, form the structure of each channel. One beta subunit, produced from the KCNE2 gene, attaches (binds) to the channel and regulates its activity.

Source: MedlinePlus, National Library of Medicine. Source publication: 2020-08-18. Source review: 2017-05.

ClinGen reviews

ClinGen reviews the evidence linking a particular gene to a condition. Each rating below describes the strength of that link. It does not classify a variant in your DNA file.

Condition	Inheritance	Evidence
long QT syndromeMONDO:0002442 · Evaluated 2018-09-25	Autosomal dominant	DefinitiveLong QT syndrome Gene Curation Expert Panel
short QT syndromeMONDO:0000453 · Evaluated 2020-08-03	Autosomal dominant	DefinitiveShort QT syndrome Gene Curation Expert Panel
Brugada syndromeMONDO:0015263 · Evaluated 2025-06-10	Autosomal dominant	DisputedHereditary Cardiovascular Disease Gene Curation Expert Panel

ClinVar records

These numbers show what has been submitted to ClinVar. They cannot tell you how likely you are to have a condition.

Submitted alleles: 4,011
Submissions for variants in or overlapping this gene: 8,631
Submissions explicitly reporting this gene: 8,447
Alleles reported pathogenic / likely pathogenic: 798
VariationIDs with uncertain significance: 1,543
VariationIDs with conflicting classifications: 287

The rows count different things: alleles, submissions or VariationIDs. Their categories can overlap, so do not add them together. Pathogenic/likely pathogenic counts exclude structural variants that merely overlap a gene. A dash in the source means “not reported,” not zero.

NCBI produces the gene-summary file each week using counts recorded at the start of the month. The numbers may differ from those on the live ClinVar website. Read the field definitions ↗

View this gene in ClinVar ↗

YOUR DNA FILE

Can your DNA file tell you about KCNH2?

From a DNA test kit (such as 23andMe, AncestryDNA or MyHeritage). These kits check a fixed list of about 600,000 to 700,000 positions across your whole genome. ClinVar lists 798 alleles in KCNH2 reported as pathogenic or likely pathogenic. A kit checks only some of these positions, and often none of them.

From whole genome sequencing (a VCF file). Sequencing reads most of your genome. Your file lists the places where your DNA differs from the reference genome. Some regions are hard to sequence, including parts of some genes that have near-identical copies elsewhere, and a VCF file does not record which positions were read well.

If a variant is not in your file, that does not mean you don’t have it.

What BioDecode checks

BioDecode compares every variant in your file with ClinVar, on your own computer. For each match, it shows the ClinVar classification, the review status and the condition it was reported for. Your file is not uploaded.

A ClinVar classification applies to one particular variant and the condition it was reported for. It does not tell you about other variants in KCNH2.

BioDecode cannot fill gaps in your test, diagnose a condition or replace clinical testing.

Buy BioDecode See a sample report →Check file compatibility →