7-150951712-C-T

Variant names:

• chr7-150951712-C-T
• rs199472921
• NM_000238.4:c.1681G>A

Variant summary

Our verdict is Pathogenic. The variant received 23 ACMG points: 23P and 0B. PS3 PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000238.4(KCNH2):​c.1681G>A​(p.Ala561Thr) 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. Variant has been reported in ClinVar as Pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV000234108: Published functional studies demonstrate that the p.(A561T) mutant channel expressed in human embryonic kidney cells failed to generate HERG current and causes defective trafficking of the KCNH2 protein to the plasma membrane (PMID:23303164, 15120823)" and additional evidence is available in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A561V) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: KCNH2 NM_000238.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3 O:1
• Conservation: PhyloP100: 7.72
• Publications: 64 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), G2P, Ambry Genetics
• short QT syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• 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: Pathogenic. The variant received 23 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV000234108: Published functional studies demonstrate that the p.(A561T) mutant channel expressed in human embryonic kidney cells failed to generate HERG current and causes defective trafficking of the KCNH2 protein to the plasma membrane (PMID: 23303164, 15120823); SCV000737602: Functional assays have demonstrated that the mutation has a dominant negative effect on protein localization and function (Bellocq C et al. Mol Pharmacol. 2004;66(5):1093-102; Chugh SS et al. J Am Coll Cardiol. 2004;43(9):1625-9; Anderson CL et al. Circulation. 2006;113(3):365-73; Mehta A et al. Cardiovasc Res. 2014; 102(3):497-506).; SCV001591955: Experimental studies have shown that this missense change affects KCNH2 function (PMID: 16432067, 23303164, 23470493).
• PM1: In a hotspot region, there are 15 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 25 uncertain in NM_000238.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr7-150951711-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 14420.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• 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, short QT syndrome type 1, short QT syndrome, Brugada syndrome, long QT syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.99
• PP5: Variant 7-150951712-C-T is Pathogenic according to our data. Variant chr7-150951712-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 67229.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNH2	NM_000238.4	MANE Select	c.1681G>A	p.Ala561Thr	missense	Exon 7 of 15	NP_000229.1	A0A090N8Q0
	KCNH2	NM_001406753.1		c.1393G>A	p.Ala465Thr	missense	Exon 5 of 13	NP_001393682.1	Q12809-7
	KCNH2	NM_172056.3		c.1681G>A	p.Ala561Thr	missense	Exon 7 of 9	NP_742053.1	Q12809-5

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNH2	ENST00000262186.10	TSL:1 MANE Select	c.1681G>A	p.Ala561Thr	missense	Exon 7 of 15	ENSP00000262186.5	Q12809-1
	KCNH2	ENST00000330883.9	TSL:1	c.661G>A	p.Ala221Thr	missense	Exon 3 of 11	ENSP00000328531.4	Q12809-2
	KCNH2	ENST00000461280.2	TSL:1	n.979G>A		non_coding_transcript_exon	Exon 3 of 5

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD2 exomes AF: 0.00 AC: 0 AN: 251268 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1461720 Hom.: 0 Cov.: 36 AF XY: 0.00 AC XY: 0 AN XY: 727136

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39692

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53376

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111900

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 34

Alfa AF: 0.0000161 Hom.: 1

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
1	-	-	Cardiovascular phenotype (1)
1	-	-	Long QT syndrome (1)
1	-	-	not provided (1)
-	-	-	Congenital long QT syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
CardioboostArm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.55
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D
Eigen	Uncertain	0.61
Eigen_PC	Uncertain	0.54
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.92	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.6	M
PhyloP100		7.7
PrimateAI	Pathogenic	0.87	D
PROVEAN	Uncertain	-3.9	D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0060	D
Polyphen		0.99	D
Vest4		0.92
MutPred		0.91		Loss of stability (P = 0.1197)
MVP		1.0
MPC		2.1
ClinPred		0.99	D
GERP RS		4.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.84
gMVP		0.96
Mutation Taster		=11/89	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs199472921; hg19: chr7-150648800; COSMIC: COSV51139156;