Genetic Variant KCNH2:p.Gly21Ala (chr7-150955442-C-G) – ACMG Classification: Uncertain_significance (1 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 3P and 2B. PM2PP2BP4_Moderate

The ENST00000330883.9(KCNH2):c.62G>C(p.Gly21Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000141 in 1,413,506 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 11/18 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G21D) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 34)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

KCNH2
ENST00000330883.9 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 1.74

Publications

0 publications found

Variant links:

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

KCNH2 links:

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ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 158 curated pathogenic missense variants (we use a threshold of 10). The gene has 38 curated benign missense variants. Gene score misZ: 3.3724 (above the threshold of 3.09). Trascript score misZ: 2.8194 (below the threshold of 3.09). GenCC associations: The gene is linked to long QT syndrome 2, Brugada syndrome, short QT syndrome type 1, short QT syndrome, long QT syndrome.

BP4

Computational evidence support a benign effect (MetaRNN=0.103153676).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNH2	NM_000238.4 link	c.1128+1849G>C		intron_variant	Intron 5 of 14	ENST00000262186.10	NP_000229.1	Q12809-1Q15BH2A0A090N8Q0

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNH2	ENST00000262186.10 link	c.1128+1849G>C		intron_variant	Intron 5 of 14	1	NM_000238.4	ENSP00000262186.5		Q12809-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

0.00000141

AC:

AN:

1413506

Hom.:

Cov.:

AF XY:

0.00000143

AC XY:

AN XY:

698904

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

32140

American (AMR)

AF:

0.00

AC:

AN:

38666

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25294

East Asian (EAS)

AF:

0.00

AC:

AN:

36684

South Asian (SAS)

AF:

0.00

AC:

AN:

80130

European-Finnish (FIN)

AF:

0.00

AC:

AN:

48852

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5116

European-Non Finnish (NFE)

AF:

0.00000184

AC:

AN:

1088192

Other (OTH)

AF:

0.00

AC:

AN:

58432

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Cov.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.098

BayesDel_addAF

Uncertain

0.016

BayesDel_noAF

Benign

-0.21

CADD

Benign

(source)

DANN

Benign

0.96

Eigen

Benign

-0.43

Eigen_PC

Benign

-0.20

FATHMM_MKL

Benign

0.22

LIST_S2

Benign

0.59

M_CAP

Uncertain

0.18

MetaRNN

Benign

0.10

MetaSVM

Uncertain

0.20

PhyloP100

1.7

PROVEAN

Benign

-0.45

REVEL

Uncertain

0.31

Sift

Benign

0.59

Sift4G

Benign

0.45

Polyphen

0.0010

Vest4

0.10

MutPred

0.30

Loss of loop (P = 9e-04);

MVP

0.43

ClinPred

0.28

GERP RS

4.1

PromoterAI

-0.035

Neutral

(source)

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Mutation Taster

=85/15

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over