rs199473495

Positions:

• chr7-150974758-A-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3 PP5

The NM_000238.4(KCNH2):​c.260T>C​(p.Leu87Pro) 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 Likely pathogenic (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L87V) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 34)
• Consequence: KCNH2 NM_000238.4 missense
• Clinical Significance: Likely pathogenic no assertion criteria provided P:2 O:1
• Conservation: PhyloP100: 7.21

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 6 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 15 uncertain in NM_000238.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.834
• PP5: Variant 7-150974758-A-G is Pathogenic according to our data. Variant chr7-150974758-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 67418.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr7-150974758-A-G is described in Lovd as [Pathogenic]. Variant chr7-150974758-A-G is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNH2	NM_000238.4	c.260T>C	p.Leu87Pro	missense_variant	2/15	ENST00000262186.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNH2	ENST00000262186.10	c.260T>C	p.Leu87Pro	missense_variant	2/15	1	NM_000238.4	P1
KCNH2	ENST00000532957.5	n.483T>C		non_coding_transcript_exon_variant	2/9	2

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 34

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2 Other:1

Revision: no assertion criteria provided

Submissions by phenotype

not provided Pathogenic:2

Likely pathogenic, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, University Medical Center Utrecht	-	- -
Likely pathogenic, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -

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:12402336;PMID:12566525;PMID:19841300). 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	0.92
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.15
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.95	D;D
Eigen	Uncertain	0.60
Eigen_PC	Uncertain	0.49
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.91	D;D
M_CAP	Pathogenic	0.99	D
MetaRNN	Pathogenic	0.83	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.2	M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.95	D
PROVEAN	Uncertain	-3.6	D;.
REVEL	Pathogenic	0.85
Sift	Uncertain	0.023	D;.
Sift4G	Benign	0.21	T;T
Polyphen		0.91	P;.
Vest4		0.58
MVP		0.96
MPC		2.6
ClinPred		0.98	D
GERP RS		4.4
Varity_R		0.96
gMVP		0.99

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: rs199473495; hg19: chr7-150671846; COSMIC: COSV100058976;