7-150957320-T-C

Position:

• chr7-150957320-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_000238.4(KCNH2):​c.1099A>G​(p.Thr367Ala) 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T367S) has been classified as Benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: KCNH2 NM_000238.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.97

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 Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.791

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNH2	NM_000238.4	c.1099A>G	p.Thr367Ala	missense_variant	5/15	ENST00000262186.10	NP_000229.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNH2	ENST00000262186.10	c.1099A>G	p.Thr367Ala	missense_variant	5/15	1	NM_000238.4	ENSP00000262186	P1
KCNH2	ENST00000532957.5	n.1322A>G		non_coding_transcript_exon_variant	5/9	2
KCNH2	ENST00000684241.1	n.1932A>G		non_coding_transcript_exon_variant	3/13

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Long QT syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 09, 2020

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with KCNH2-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces threonine with alanine at codon 367 of the KCNH2 protein (p.Thr367Ala). The threonine residue is moderately conserved and there is a small physicochemical difference between threonine and alanine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.72
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.20
CADD	Pathogenic	26
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.78	D;T
Eigen	Uncertain	0.29
Eigen_PC	Uncertain	0.32
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.93	D;D
M_CAP	Uncertain	0.16	D
MetaRNN	Pathogenic	0.79	D;D
MetaSVM	Uncertain	0.45	D
MutationAssessor	Uncertain	2.4	M;.
MutationTaster	Benign	0.97	D;D;D
PrimateAI	Uncertain	0.79	T
PROVEAN	Uncertain	-3.6	D;.
REVEL	Pathogenic	0.72
Sift	Uncertain	0.015	D;.
Sift4G	Benign	0.12	T;T
Polyphen		0.61	P;.
Vest4		0.68
MutPred		0.55		Loss of phosphorylation at T367 (P = 0.0404);.;
MVP		0.99
MPC		1.2
ClinPred		0.89	D
GERP RS		3.7
Varity_R		0.20
gMVP		0.80

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: rs199472890; hg19: chr7-150654408; COSMIC: COSV51169240; COSMIC: COSV51169240;