7-150947057-G-A

Position:

• chr7-150947057-G-A

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_Strong BP6 BS2_Supporting

The NM_000238.4(KCNH2):​c.3153-3C>T variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000339 in 1,592,274 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000033 (0 hom., cov: 31)
  • Exomes 𝑓: 0.000034 (1 hom.)
• Consequence: KCNH2 NM_000238.4 splice_region, intron
• Scores: Splicing: ADA: 0.006324
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 0.266

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 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -6 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.52).
• BP6: Variant 7-150947057-G-A is Benign according to our data. Variant chr7-150947057-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 456923.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.
• BS2: High AC in GnomAd4 at 5 AD,Digenic gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNH2	NM_000238.4	c.3153-3C>T		splice_region_variant, intron_variant		ENST00000262186.10	NP_000229.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNH2	ENST00000262186.10	c.3153-3C>T		splice_region_variant, intron_variant		1	NM_000238.4	ENSP00000262186.5
KCNH2	ENST00000330883.9	c.2133-3C>T		splice_region_variant, intron_variant		1		ENSP00000328531.4
KCNH2	ENST00000684241.1	n.3986-3C>T		splice_region_variant, intron_variant

Frequencies

GnomAD3 genomes AF: 0.0000329 AC: 5 AN: 151794 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.0000485

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000656

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000295

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000844 AC: 2 AN: 236986 Hom.: 0 AF XY: 0.00000781 AC XY: 1 AN XY: 127968

Gnomad AFR exome AF: 0.000126

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000340 AC: 49 AN: 1440480 Hom.: 1 Cov.: 33 AF XY: 0.0000280 AC XY: 20 AN XY: 713314

Gnomad4 AFR exome AF: 0.0000605

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: 0.0000428

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000329 AC: 5 AN: 151794 Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1 AN XY: 74136

Gnomad4 AFR AF: 0.0000485

Gnomad4 AMR AF: 0.0000656

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000295

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Long QT syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 19, 2023

This sequence change falls in intron 13 of the KCNH2 gene. It does not directly change the encoded amino acid sequence of the KCNH2 protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (no rsID available, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with KCNH2-related conditions. ClinVar contains an entry for this variant (Variation ID: 456923). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Cardiac arrhythmia Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Dec 03, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.52
CADD	Benign	12
DANN	Benign	0.85

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.0063
dbscSNV1_RF	Benign	0.22
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: rs1165322354; hg19: chr7-150644145;