Genetic Variant KCNH8:p.Arg277Gln (chr3-19390499-G-A) – ACMG Classification: Uncertain_significance (4 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_144633.3(KCNH8):c.830G>A(p.Arg277Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000112 in 1,608,054 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 Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

KCNH8
NM_144633.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 10.0

Variant links:

Genes affected

KCNH8 (HGNC:18864): (potassium voltage-gated channel subfamily H member 8) Voltage-gated potassium (Kv) channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. This gene encodes a member of the potassium channel, voltage-gated, subfamily H. This member is a pore-forming (alpha) subunit. [provided by RefSeq, Jul 2008]

KCNH8 links:

ENSG00000287069 (HGNC:):

ENSG00000287069 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.93

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNH8	NM_144633.3 link	c.830G>A	p.Arg277Gln	missense_variant	Exon 6 of 16	ENST00000328405.7	NP_653234.2	Q96L42-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNH8	ENST00000328405.7 link	c.830G>A	p.Arg277Gln	missense_variant	Exon 6 of 16	1	NM_144633.3	ENSP00000328813.2		Q96L42-1

Frequencies

GnomAD3 genomes

AF:

0.0000133

AC:

AN:

150378

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.0000161

AC:

AN:

248796

Hom.:

AF XY:

0.0000149

AC XY:

AN XY:

134510

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000110

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000464

Gnomad NFE exome

AF:

0.00000887

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000110

AC:

AN:

1457676

Hom.:

Cov.:

AF XY:

0.00000552

AC XY:

AN XY:

725138

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000506

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.0000376

Gnomad4 NFE exome

AF:

0.00000901

Gnomad4 OTH exome

AF:

0.0000332

GnomAD4 genome

AF:

0.0000133

AC:

AN:

150378

Hom.:

Cov.:

AF XY:

0.0000137

AC XY:

AN XY:

73200

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

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

Alfa

AF:

0.0000329

Hom.:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Sep 14, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.830G>A (p.R277Q) alteration is located in exon 6 (coding exon 6) of the KCNH8 gene. This alteration results from a G to A substitution at nucleotide position 830, causing the arginine (R) at amino acid position 277 to be replaced by a glutamine (Q). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.59

BayesDel_addAF

Pathogenic

0.40

BayesDel_noAF

Pathogenic

0.56

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.84

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.96

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.99

M_CAP

Uncertain

0.096

MetaRNN

Pathogenic

0.93

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.2

PrimateAI

Pathogenic

0.85

PROVEAN

Uncertain

-3.8

REVEL

Pathogenic

0.87

Sift

Uncertain

0.0010

Sift4G

Uncertain

0.0040

Polyphen

1.0

Vest4

0.98

MVP

0.98

MPC

1.9

ClinPred

0.94

GERP RS

5.8

Varity_R

0.54

gMVP

0.86

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.34

Details are displayed if max score is > 0.2

DS_AL_spliceai

0.34

Position offset: -18

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over