rs41307292

chr7-150950235-G-A

Variant summary

Our verdict is Benign. Variant got -10 ACMG points: 0P and 10B. BP4_Strong BP6 BP7 BS2

The NM_000238.4(KCNH2):c.2331C>T(p.Thr777=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000248 in 1,613,352 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 30)
  • Exomes 𝑓: 0.000025 (0 hom.)
• Consequence: KCNH2 NM_000238.4 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:6
• Conservation: PhyloP100: -1.46

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 Benign. Variant got -10 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.65).
• BP6: Variant 7-150950235-G-A is Benign according to our data. Variant chr7-150950235-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 359309.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=2, Likely_benign=4, Benign=2}. Variant chr7-150950235-G-A is described in Lovd as [Benign].
• BP7: Synonymous conserved (PhyloP=-1.46 with no splicing effect.
• BS2: High AC in GnomAdExome at 28 AD,Digenic gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNH2	NM_000238.4	c.2331C>T	p.Thr777=	synonymous_variant	9/15	ENST00000262186.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNH2	ENST00000262186.10	c.2331C>T	p.Thr777=	synonymous_variant	9/15	1	NM_000238.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000198 AC: 3 AN: 151726 Hom.: 0 Cov.: 30

Gnomad AFR AF: 0.0000242

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000195

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000112 AC: 28 AN: 250966 Hom.: 0 AF XY: 0.0000885 AC XY: 12 AN XY: 135642

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00125

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000264

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000253 AC: 37 AN: 1461510 Hom.: 0 Cov.: 39 AF XY: 0.0000206 AC XY: 15 AN XY: 727026

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000504

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.0000188

Gnomad4 NFE exome AF: 0.00000809

Gnomad4 OTH exome AF: 0.0000497

GnomAD4 genome AF: 0.0000198 AC: 3 AN: 151842 Hom.: 0 Cov.: 30 AF XY: 0.0000404 AC XY: 3 AN XY: 74210

Gnomad4 AFR AF: 0.0000242

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000195

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000329 Hom.: 0

Bravo AF: 0.0000756

Asia WGS AF: 0.000577 AC: 2 AN: 3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:6

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Oct 19, 2016	- -
Benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Oct 31, 2016	Variant summary: The c.2331T>C (p.Thr777=) in KCNH2 gene is a synonymous change that involves a non-conserved nucleotide. 5/5 programs in Alamut predict that this variant does not affect a normal splicing, however no functional studies supporting this notion were published at the time of evaluation. The variant is present in control population dataset of ExAC at a frequency of 0.0001 (13/120792 chrs tested), predominantly in individuals of East Asian descent (0.001; 9/8618 chrs tested). These frequencies exceed the estimated maximal expected allele frequency of a pathogenic variant in KCNH2 gene (0.0001). The variant has not, to our knowledge, been reported in affected individuals via publications but was reported as a polymorphism in healthy Chinese controls (Koo, 2006). A clinical diagnostic laboratory cites the variant as a "VOUS." Therefore, taking all available lines of evidence into consideration, the variant of interest has been classified as Benign. -

Long QT syndrome Benign:2

Benign, criteria provided, single submitter	clinical testing	Invitae	Jan 18, 2024	- -
Likely benign, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Jan 11, 2024	- -

Long QT syndrome 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Apr 28, 2016

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Cardiovascular phenotype Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 20, 2019

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Cardiac arrhythmia Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Nov 18, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.65
Cadd	Benign	7.4
Dann	Benign	0.90
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs41307292; hg19: chr7-150647323; COSMIC: COSV51126031;