rs121912505

Positions:

• chr7-150952574-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1 PM2 PP3_Strong PP5

The ENST00000262186.10(KCNH2):​c.1408A>G​(p.Asn470Asp) 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. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars). Synonymous variant affecting the same amino acid position (i.e. N470N) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: KCNH2 ENST00000262186.10 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1 O:1
• Conservation: PhyloP100: 7.86

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 10 uncertain in ENST00000262186.10
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.984
• PP5: Variant 7-150952574-T-C is Pathogenic according to our data. Variant chr7-150952574-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 14421.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr7-150952574-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNH2	NM_000238.4	c.1408A>G	p.Asn470Asp	missense_variant	6/15	ENST00000262186.10	NP_000229.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNH2	ENST00000262186.10	c.1408A>G	p.Asn470Asp	missense_variant	6/15	1	NM_000238.4	ENSP00000262186	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1 Other:1

Revision: no assertion criteria provided

Submissions by phenotype

Long QT syndrome 2 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Feb 17, 2006

- -

Congenital long QT syndrome Other:1

not provided, no classification provided

literature only

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

-

This variant has been reported as associated with Long QT syndrome in the following publications (PMID:7889573;PMID:16432067). 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 v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.25
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.99	.;D;D
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.77
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Pathogenic	0.94	D
MetaRNN	Pathogenic	0.98	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.1	.;H;.
MutationTaster	Benign	1.0	A;A;A;A
PrimateAI	Pathogenic	0.84	D
PROVEAN	Pathogenic	-4.5	D;D;.
REVEL	Pathogenic	0.95
Sift	Uncertain	0.0010	D;D;.
Sift4G	Uncertain	0.0030	D;D;D
Polyphen		1.0	D;D;.
Vest4		0.99
MutPred		0.87		.;Gain of glycosylation at T474 (P = 0.2937);.;
MVP		0.99
MPC		2.3
ClinPred		1.0	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.98
gMVP		0.99

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

Publications

LitVar

Other links and lift over

dbSNP: rs121912505; hg19: chr7-150649662;