rs1056770175

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_005477.3(HCN4):c.379G>A(p.Glu127Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000029 in 1,378,094 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E127G) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000024 ( 0 hom. )

Consequence

HCN4
NM_005477.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 2.64

Publications

0 publications found

Variant links:

Genes affected

HCN4 (HGNC:16882): (hyperpolarization activated cyclic nucleotide gated potassium channel 4) This gene encodes a member of the hyperpolarization-activated cyclic nucleotide-gated potassium channels. The encoded protein shows slow kinetics of activation and inactivation, and is necessary for the cardiac pacemaking process. This channel may also mediate responses to sour stimuli. Mutations in this gene have been linked to sick sinus syndrome 2, also known as atrial fibrillation with bradyarrhythmia or familial sinus bradycardia. Two pseudogenes have been identified on chromosome 15. [provided by RefSeq, Oct 2008]

HCN4 Gene-Disease associations (from GenCC):

sick sinus syndrome 2, autosomal dominant
Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics
Brugada syndrome 8
Inheritance: AD Classification: MODERATE, LIMITED Submitted by: Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
familial sick sinus syndrome
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
familial thoracic aortic aneurysm and aortic dissection
Inheritance: AD Classification: LIMITED Submitted by: ClinGen
Brugada syndrome 1
Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

HCN4 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HCN4	NM_005477.3 link	c.379G>A	p.Glu127Lys	missense_variant	Exon 1 of 8	ENST00000261917.4	NP_005468.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HCN4	ENST00000261917.4 link	c.379G>A	p.Glu127Lys	missense_variant	Exon 1 of 8	1	NM_005477.3	ENSP00000261917.3

Frequencies

GnomAD3 genomes

AF:

0.00000660

AC:

AN:

151414

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:

0.0000148

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000245

AC:

AN:

1226680

Hom.:

Cov.:

AF XY:

0.00000166

AC XY:

AN XY:

600670

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

25816

American (AMR)

AF:

0.00

AC:

AN:

24108

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

19738

East Asian (EAS)

AF:

0.00

AC:

AN:

28100

South Asian (SAS)

AF:

0.00

AC:

AN:

51742

European-Finnish (FIN)

AF:

0.00

AC:

AN:

28146

Middle Eastern (MID)

AF:

0.00

AC:

AN:

3548

European-Non Finnish (NFE)

AF:

0.00000301

AC:

AN:

996360

Other (OTH)

AF:

0.00

AC:

AN:

49122

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.458

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

AF:

0.00000660

AC:

AN:

151414

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

73920

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

41372

American (AMR)

AF:

0.00

AC:

AN:

15206

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3464

East Asian (EAS)

AF:

0.00

AC:

AN:

5178

South Asian (SAS)

AF:

0.00

AC:

AN:

4836

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10302

Middle Eastern (MID)

AF:

0.00

AC:

AN:

314

European-Non Finnish (NFE)

AF:

0.0000148

AC:

AN:

67750

Other (OTH)

AF:

0.00

AC:

AN:

2080

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.325

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome 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

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Brugada syndrome 8

Uncertain:1

Mar 26, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 127 of the HCN4 protein (p.Glu127Lys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with HCN4-related conditions. ClinVar contains an entry for this variant (Variation ID: 577931). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt HCN4 protein function with a negative predictive value of 95%. 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.

Cardiovascular phenotype

Uncertain:1

Nov 04, 2021

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.E127K variant (also known as c.379G>A), located in coding exon 1 of the HCN4 gene, results from a G to A substitution at nucleotide position 379. The glutamic acid at codon 127 is replaced by lysine, an amino acid with similar properties. This alteration has been reported in an individual with familial thoracic aortic aneurysm, having an additional alteration in MYLK identified (Schweizer PA et al. J Am Coll Cardiol, 2017 03;69:1209-1210). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.48

BayesDel_addAF

Pathogenic

0.18

BayesDel_noAF

Uncertain

0.020

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.27

Eigen

Uncertain

0.44

Eigen_PC

Uncertain

0.38

LIST_S2

Uncertain

0.89

M_CAP

Pathogenic

0.88

MetaRNN

Uncertain

0.51

MetaSVM

Pathogenic

1.0

MutationAssessor

Benign

1.8

PhyloP100

2.6

PrimateAI

Pathogenic

0.97

PROVEAN

Benign

-0.75

Sift

Uncertain

0.0020

Sift4G

Uncertain

0.029

Vest4

0.25

ClinPred

0.82

GERP RS

3.0

Varity_R

0.33

gMVP

0.59

Mutation Taster

=58/42

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over