rs199472857

Positions:

• chr7-150974713-T-A
• chr7-150974713-T-G

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_000238.4(KCNH2):​c.305A>T​(p.Asp102Val) variant causes a missense, splice region change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as not provided (no stars).

• Frequency: Genomes: not found (cov: 33)
• Consequence: KCNH2 NM_000238.4 missense, splice_region
• Scores: Splicing: ADA: 0.6099
• Clinical Significance: not provided no classification provided O:1
• Conservation: PhyloP100: 4.98

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 8 ACMG points.

• PM1: In a domain PAC (size 52) in uniprot entity KCNH2_HUMAN there are 11 pathogenic changes around while only 1 benign (92%) in NM_000238.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.984

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNH2	NM_000238.4	c.305A>T	p.Asp102Val	missense_variant, splice_region_variant	2/15	ENST00000262186.10	NP_000229.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNH2	ENST00000262186.10	c.305A>T	p.Asp102Val	missense_variant, splice_region_variant	2/15	1	NM_000238.4	ENSP00000262186	P1
KCNH2	ENST00000532957.5	n.528A>T		splice_region_variant, non_coding_transcript_exon_variant	2/9	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

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:18752142;PMID:19862833). 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	0.91
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.52
CADD	Pathogenic	34
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.94	D;D
Eigen	Uncertain	0.39
Eigen_PC	Uncertain	0.30
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.91	D;D
M_CAP	Pathogenic	0.99	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.2	H;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.76	T
PROVEAN	Pathogenic	-4.9	D;.
REVEL	Pathogenic	0.88
Sift	Uncertain	0.0010	D;.
Sift4G	Uncertain	0.0020	D;D
Polyphen		0.46	P;.
Vest4		0.83
MutPred		0.87		Gain of methylation at K101 (P = 0.0222);.;
MVP		1.0
MPC		2.5
ClinPred		1.0	D
GERP RS		3.2
Varity_R		0.97
gMVP		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.61
dbscSNV1_RF	Benign	0.60
SpliceAI score (max)		0.16		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: rs199472857; hg19: chr7-150671801;