rs794728402

chr7-150947473-C-Achr7-150947473-C-Gchr7-150947473-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP3_Moderate PP5

The NM_000238.4(KCNH2):c.3007G>T(p.Asp1003Tyr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000702 in 1,424,966 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D1003N) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.0e-7 (0 hom.)
• Consequence: KCNH2 NM_000238.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 7.66

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 Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.863
• PP5: Variant 7-150947473-C-A is Pathogenic according to our data. Variant chr7-150947473-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 200516.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNH2	NM_000238.4	c.3007G>T	p.Asp1003Tyr	missense_variant	13/15	ENST00000262186.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNH2	ENST00000262186.10	c.3007G>T	p.Asp1003Tyr	missense_variant	13/15	1	NM_000238.4	P1
KCNH2	ENST00000330883.9	c.1987G>T	p.Asp663Tyr	missense_variant	9/11	1
KCNH2	ENST00000684241.1	n.3840G>T		non_coding_transcript_exon_variant	11/13

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000535 AC: 1 AN: 186764 Hom.: 0 AF XY: 0.00000987 AC XY: 1 AN XY: 101364

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000707

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: 7.02e-7 AC: 1 AN: 1424966 Hom.: 0 Cov.: 36 AF XY: 0.00000142 AC XY: 1 AN XY: 705282

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000262

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jul 16, 2014

p.Asp1003Tyr (GAC>TAC): c.3007 G>T in exon 13 of the KCNH2 gene (NM_000238.2). The D1003Y variant that is likely pathogenic was identified in the KCNH2 gene. The D1003Y variant in the KCNH2 gene has not been reported as a disease-causing mutation or as a benign polymorphism to our knowledge. The D1003Y variant is a non-conservative amino acid substitution as these residues differ in polarity, charge, size and/or other properties and is more likely to impact secondary structure. The D1003Y residue is class conserved across species. In silico analysis predicts D1003Y is damaging to the protein structure/function. Mutations in nearby residues (N996I, R1005Q, R1007H) have been reported in association with LQTS, further supporting the functional importance of this region of the protein. Furthermore, the D1003Y variant was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. Therefore, this variant is a strong candidate for a pathogenic mutation, however the possibility that it is a benign variant cannot be excluded. The variant is found in LQT panel(s). -

Cardiac arrhythmia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Jul 31, 2023

This missense variant replaces aspartic acid with tyrosine at codon 1003 of the KCNH2 protein. Computational prediction suggests that this variant may have a deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with KCNH2-related disorders in the literature. This variant has been identified in 1/186764 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.38
CardioboostArm	Benign	0.060
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Pathogenic	0.32
Cadd	Pathogenic	27
Dann	Uncertain	1.0
Eigen	Uncertain	0.55
Eigen_PC	Uncertain	0.57
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.93	D;D
M_CAP	Pathogenic	0.75	D
MetaRNN	Pathogenic	0.86	D;D
MetaSVM	Pathogenic	1.1	D
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.67	T
PROVEAN	Uncertain	-3.5	D;D
REVEL	Pathogenic	0.84
Sift	Uncertain	0.0060	D;D
Sift4G	Uncertain	0.0070	D;D
Polyphen		0.98	D;D
Vest4		0.59
MutPred		0.48		.;Gain of sheet (P = 0.0085);
MVP		0.94
MPC		0.71
ClinPred		0.94	D
GERP RS		4.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.67
gMVP		0.74

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs794728402; hg19: chr7-150644561;