rs794727637

Variant summary

Our verdict is Pathogenic. The variant received 20 ACMG points: 20P and 0B. PS1_Very_StrongPM1PM2PM5PP3_StrongPP5_Moderate

The NM_005477.3(HCN4):​c.1444G>C​(p.Gly482Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,210 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 Pathogenic (★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G482E) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 34)

Consequence

HCN4
NM_005477.3 missense

Scores

13
5
1

Clinical Significance

Pathogenic criteria provided, single submitter P:4

Conservation

PhyloP100: 7.81

Publications

21 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 20 ACMG points.

PS1
Transcript NM_005477.3 (HCN4) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
PM1
In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 12 uncertain in NM_005477.3
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr15-73329718-C-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1675065.Status of the report is criteria_provided_single_submitter, 1 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.993
PP5
Variant 15-73329719-C-G is Pathogenic according to our data. Variant chr15-73329719-C-G is described in ClinVar as Pathogenic. ClinVar VariationId is 374859.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HCN4NM_005477.3 linkc.1444G>C p.Gly482Arg missense_variant Exon 4 of 8 ENST00000261917.4 NP_005468.1 Q9Y3Q4
HCN4XM_011521148.3 linkc.226G>C p.Gly76Arg missense_variant Exon 3 of 7 XP_011519450.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HCN4ENST00000261917.4 linkc.1444G>C p.Gly482Arg missense_variant Exon 4 of 8 1 NM_005477.3 ENSP00000261917.3 Q9Y3Q4

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152210
Hom.:
0
Cov.:
34
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
Cov.:
32
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152210
Hom.:
0
Cov.:
34
AF XY:
0.0000134
AC XY:
1
AN XY:
74356
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:
0
AN:
41460
American (AMR)
AF:
0.00
AC:
0
AN:
15292
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68020
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
⚠️ 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
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not provided Pathogenic:2
-
Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
Genome Diagnostics Laboratory, University Medical Center Utrecht
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Sick sinus syndrome 2, autosomal dominant Pathogenic:1
Aug 26, 2014
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Brugada syndrome 8 Pathogenic:1
Aug 05, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

For these reasons, this variant has been classified as Pathogenic. Experimental studies have shown that this missense change affects HCN4 function (PMID: 25145517, 25145518). 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 expected to disrupt HCN4 protein function. ClinVar contains an entry for this variant (Variation ID: 374859). This missense change has been observed in individual(s) with clinical features of HCN4-related conditions (PMID: 25145517, 25145518, 26206080, 26688388, 28104484, 30471092). It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glycine with arginine at codon 482 of the HCN4 protein (p.Gly482Arg). The glycine residue is highly conserved and there is a moderate physicochemical difference between glycine and arginine. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
1.0
BayesDel_addAF
Pathogenic
0.57
D
BayesDel_noAF
Pathogenic
0.58
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.98
D
Eigen
Uncertain
0.62
Eigen_PC
Uncertain
0.45
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Pathogenic
1.0
D
M_CAP
Pathogenic
0.88
D
MetaRNN
Pathogenic
0.99
D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
3.4
M
PhyloP100
7.8
PrimateAI
Pathogenic
0.82
D
PROVEAN
Pathogenic
-7.7
D
REVEL
Pathogenic
0.98
Sift
Uncertain
0.0010
D
Sift4G
Pathogenic
0.0010
D
Polyphen
1.0
D
Vest4
0.99
MutPred
0.85
Gain of MoRF binding (P = 0.057);
MVP
0.93
MPC
1.3
ClinPred
1.0
D
GERP RS
4.2
Varity_R
0.85
gMVP
0.99
Mutation Taster
=3/97
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs794727637; hg19: chr15-73622060; API