NM_000238.4:c.1885A>G

Variant names:

• chr7-150951508-T-C
• rs199472956
• NM_000238.4:c.1885A>G

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Moderate

The NM_000238.4(KCNH2):​c.1885A>G​(p.Asn629Asp) 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N629K) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 34)
• Consequence: KCNH2 NM_000238.4 missense
• Clinical Significance: Pathogenic criteria provided, single submitter 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 Pathogenic. Variant got 12 ACMG points.

• PM1: In a intramembrane_region Pore-forming; Name=Segment H5 (size 20) in uniprot entity KCNH2_HUMAN there are 23 pathogenic changes around while only 0 benign (100%) 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 chr7-150951506-G-T is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.97
• PP5: Variant 7-150951508-T-C is Pathogenic according to our data. Variant chr7-150951508-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 67313.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr7-150951508-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNH2	NM_000238.4	c.1885A>G	p.Asn629Asp	missense_variant	Exon 7 of 15	ENST00000262186.10	NP_000229.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNH2	ENST00000262186.10	c.1885A>G	p.Asn629Asp	missense_variant	Exon 7 of 15	1	NM_000238.4	ENSP00000262186.5

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 34

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Apr 09, 2015

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The Asn629Asp mutation in the KCNH2 gene has been reported multiple times in association with LQTS (Satler C et al., 1998; Lees-Miller J et al., 2000; Anderson C et al., 2006; Teng G et al., 2008). Mutations affecting this same residue, (Asn629Ser, Asn629Ile, Asn629Lys, Asn629Thr) and nearby residues (Gly628Ala, Gly628Ser, Gly628Val, Val630Ala, Val630Leu) in the highly conserved pore region have been reported in association with LQTS, further supporting the functional importance of this residue and this region of the protein. Furthermore, Asn629Asp was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The variant is found in LQT panel(s). -

Congenital 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 Long QT syndrome in the following publications (PMID:9544837;PMID:10517660;PMID:10720411;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	0.23	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.94	.;D;D
Eigen	Uncertain	0.35
Eigen_PC	Uncertain	0.32
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Pathogenic	1.0	D;D;D
M_CAP	Pathogenic	0.67	D
MetaRNN	Pathogenic	0.97	D;D;D
MetaSVM	Uncertain	0.78	D
MutationAssessor	Benign	1.3	.;L;.
PrimateAI	Pathogenic	0.87	D
PROVEAN	Pathogenic	-4.9	D;D;.
REVEL	Pathogenic	0.83
Sift	Pathogenic	0.0	D;D;.
Sift4G	Uncertain	0.0040	D;D;D
Polyphen		0.94	P;D;.
Vest4		0.95
MutPred		0.83		.;Gain of sheet (P = 0.0827);.;
MVP		0.95
MPC		2.3
ClinPred		1.0	D
GERP RS		4.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.90
gMVP		0.99

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs199472956; hg19: chr7-150648596;