rs199472911

Positions:

• chr7-150952504-T-A
• chr7-150952504-T-C
• chr7-150952504-T-G

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_000238.4(KCNH2):​c.1478A>T​(p.Tyr493Phe) 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 not provided (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y493C) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: KCNH2 NM_000238.4 missense
• Clinical Significance: not provided no classification provided 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 10 ACMG points.

• PM1: In a topological_domain Cytoplasmic (size 23) in uniprot entity KCNH2_HUMAN there are 4 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 chr7-150952504-T-C is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNH2	NM_000238.4	c.1478A>T	p.Tyr493Phe	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.1478A>T	p.Tyr493Phe	missense_variant	6/15	1	NM_000238.4	ENSP00000262186	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 40

GnomAD4 genome Cov.: 33

ClinVar

Significance: not provided

Submissions summary: Other:1

Revision: no classification provided

Submissions by phenotype

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:19668779). 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	0.93
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	26
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.98	.;D;D
Eigen	Pathogenic	0.95
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Pathogenic	1.0	D;D;D
M_CAP	Pathogenic	0.96	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	0.93	D
MutationAssessor	Pathogenic	3.4	.;M;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.83	D
PROVEAN	Uncertain	-3.7	D;D;.
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D;D;.
Sift4G	Uncertain	0.010	D;D;D
Polyphen		1.0	D;D;.
Vest4		0.91
MutPred		0.96		.;Loss of sheet (P = 0.0457);.;
MVP		0.99
MPC		2.1
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.87
gMVP		0.98

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

Publications

LitVar

Other links and lift over

dbSNP: rs199472911; hg19: chr7-150649592;