rs1255299868

Positions:

• chr7-150958243-C-A
• chr7-150958243-C-T

Variant summary

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

The ENST00000262186.10(KCNH2):​c.732G>T​(p.Ala244=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00002 in 1,251,014 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: not found (cov: 33)
  • Exomes 𝑓: 0.000020 (0 hom.)
• Consequence: KCNH2 ENST00000262186.10 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:3
• Conservation: PhyloP100: -2.58

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=-0.61).
• BP6: Variant 7-150958243-C-A is Benign according to our data. Variant chr7-150958243-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 509421.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Likely_benign=3}.
• BP7: Synonymous conserved (PhyloP=-2.58 with no splicing effect.
• BS2: High AC in GnomAdExome4 at 25 AD,Digenic gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNH2	NM_000238.4	c.732G>T	p.Ala244=	synonymous_variant	4/15	ENST00000262186.10	NP_000229.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNH2	ENST00000262186.10	c.732G>T	p.Ala244=	synonymous_variant	4/15	1	NM_000238.4	ENSP00000262186	P1
KCNH2	ENST00000532957.5	n.955G>T		non_coding_transcript_exon_variant	4/9	2
KCNH2	ENST00000684241.1	n.1565G>T		non_coding_transcript_exon_variant	2/13

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.0000200 AC: 25 AN: 1251014 Hom.: 0 Cov.: 32 AF XY: 0.0000212 AC XY: 13 AN XY: 613030

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000247

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Long QT syndrome 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

May 05, 2017

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. -

Long QT syndrome Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 18, 2023

- -

Cardiovascular phenotype Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 01, 2024

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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.61
CADD	Benign	1.8
DANN	Benign	0.77

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1255299868; hg19: chr7-150655331;