rs41307292

Variant names:

• chr7-150950235-G-A
• rs41307292
• NM_000238.4:c.2331C>T

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 0P and 10B. BP4_Strong BP6 BP7 BS2

The NM_000238.4(KCNH2):​c.2331C>T​(p.Thr777Thr) 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
• Publications: 0 publications found

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]

KCNH2 Gene-Disease associations (from GenCC):

• long QT syndrome

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• long QT syndrome 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
• short QT syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• short QT syndrome type 1

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• Brugada syndrome

  Inheritance: AD Classification: MODERATE, NO_KNOWN Submitted by: ClinGen, Genomics England PanelApp

ACMG classification

Our verdict: Benign. The variant received -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 VariationId is 359309.
• BP7: Synonymous conserved (PhyloP=-1.46 with no splicing effect.
• BS2: High AC in GnomAdExome4 at 37 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNH2	NM_000238.4	c.2331C>T	p.Thr777Thr	synonymous_variant	Exon 9 of 15	ENST00000262186.10	NP_000229.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNH2	ENST00000262186.10	c.2331C>T	p.Thr777Thr	synonymous_variant	Exon 9 of 15	1	NM_000238.4	ENSP00000262186.5

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

GnomAD2 exomes AF: 0.000112 AC: 28 AN: 250966 AF XY: 0.0000885

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 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

African (AFR) AF: 0.0000299 AC: 1 AN: 33478

American (AMR) AF: 0.0000224 AC: 1 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26104

East Asian (EAS) AF: 0.000504 AC: 20 AN: 39692

South Asian (SAS) AF: 0.0000232 AC: 2 AN: 86244

European-Finnish (FIN) AF: 0.0000188 AC: 1 AN: 53284

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00000809 AC: 9 AN: 1111840

Other (OTH) AF: 0.0000497 AC: 3 AN: 60384

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

African (AFR) AF: 0.0000242 AC: 1 AN: 41378

American (AMR) AF: 0.00 AC: 0 AN: 15278

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.000195 AC: 1 AN: 5118

South Asian (SAS) AF: 0.00 AC: 0 AN: 4806

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10560

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 67918

Other (OTH) AF: 0.00 AC: 0 AN: 2106

Alfa AF: 0.000151 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

Oct 31, 2016

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. -

Oct 19, 2016

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Long QT syndrome Benign:2

Jan 11, 2024

All of Us Research Program, National Institutes of Health

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 12, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Long QT syndrome 2 Uncertain:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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

Apr 28, 2016

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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

Dec 20, 2019

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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

Nov 18, 2018

Color Diagnostics, LLC DBA Color Health

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.65
CADD	Benign	7.4
DANN	Benign	0.90
PhyloP100		-1.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=98/2	polymorphism

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

Other links and lift over

dbSNP: rs41307292; hg19: chr7-150647323; COSMIC: COSV51126031;