7-150950949-G-A

Variant names:

• chr7-150950949-G-A
• rs199472985
• NM_000238.4:c.2117C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM2 PP2 PP3_Strong

The NM_000238.4(KCNH2):​c.2117C>T​(p.Ser706Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 14/23 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as not provided (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S706C) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: KCNH2 NM_000238.4 missense
• Clinical Significance: not provided no classification provided O:1
• Conservation: PhyloP100: 9.95
• Publications: 12 publications found

Genes affected

KCNH2 (HGNC:6251): (potassium voltage-gated channel subfamily H member 2) This gene encodes a component of a voltage-activated potassium channel found in cardiac muscle, nerve cells, and microglia. Four copies of this protein interact with one copy of the KCNE2 protein to form a functional potassium channel. Mutations in this gene can cause long QT syndrome type 2 (LQT2). Transcript variants encoding distinct isoforms have been identified. [provided by RefSeq, May 2022]

KCNH2 Gene-Disease associations (from GenCC):

• long QT syndrome

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• long QT syndrome 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
• short QT syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• short QT syndrome type 1

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• Brugada syndrome

  Inheritance: AD Classification: MODERATE, NO_KNOWN Submitted by: ClinGen, Genomics England PanelApp

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 158 curated pathogenic missense variants (we use a threshold of 10). The gene has 38 curated benign missense variants. Gene score misZ: 3.3724 (above the threshold of 3.09). Trascript score misZ: 2.4846 (below the threshold of 3.09). GenCC associations: The gene is linked to long QT syndrome 2, Brugada syndrome, short QT syndrome type 1, short QT syndrome, long QT syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.971

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000238.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNH2	NM_000238.4	MANE Select	c.2117C>T	p.Ser706Phe	missense	Exon 8 of 15	NP_000229.1
	KCNH2	NM_001406753.1		c.1829C>T	p.Ser610Phe	missense	Exon 6 of 13	NP_001393682.1
	KCNH2	NM_172056.3		c.2117C>T	p.Ser706Phe	missense	Exon 8 of 9	NP_742053.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNH2	ENST00000262186.10	TSL:1 MANE Select	c.2117C>T	p.Ser706Phe	missense	Exon 8 of 15	ENSP00000262186.5
	KCNH2	ENST00000330883.9	TSL:1	c.1097C>T	p.Ser366Phe	missense	Exon 4 of 11	ENSP00000328531.4
	KCNH2	ENST00000461280.2	TSL:1	n.1415C>T		non_coding_transcript_exon	Exon 4 of 5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: not provided

Submissions summary: Other:1

Revision: no classification provided

Submissions by phenotype

Acquired long QT syndrome Other:1

Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

This variant has been reported as associated with acquired long QT syndrome in the following publications (PMID:19843919). This is a literature report, and does not necessarily reflect the clinical interpretation of the Imperial College / Royal Brompton Cardiovascular Genetics laboratory.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
CardioboostArm	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.90	D
Eigen	Pathogenic	0.71
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.85	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.2	M
PhyloP100		9.9
PrimateAI	Pathogenic	0.80	T
PROVEAN	Pathogenic	-5.1	D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.93
MutPred		0.85		Gain of helix (P = 0.1736)
MVP		0.99
MPC		2.2
ClinPred		1.0	D
GERP RS		4.4
Varity_R		0.88
gMVP		0.94
Mutation Taster		=0/100	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs199472985; hg19: chr7-150648037;