rs878854774

Variant names:

• chr15-73322786-T-C
• rs878854774
• NM_005477.3:c.3307A>G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_005477.3(HCN4):​c.3307A>G​(p.Arg1103Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000714 in 1,401,408 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.1e-7 (0 hom.)
• Consequence: HCN4 NM_005477.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.00300
• Publications: 0 publications found

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: DEFINITIVE, STRONG Submitted by: ClinGen, Ambry Genetics, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• Brugada syndrome 8

  Inheritance: AD Classification: MODERATE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
• familial sick sinus syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Brugada syndrome 1

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.19790885).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005477.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HCN4	NM_005477.3	MANE Select	c.3307A>G	p.Arg1103Gly	missense	Exon 8 of 8	NP_005468.1	Q9Y3Q4

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HCN4	ENST00000261917.4	TSL:1 MANE Select	c.3307A>G	p.Arg1103Gly	missense	Exon 8 of 8	ENSP00000261917.3	Q9Y3Q4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 7.14e-7 AC: 1 AN: 1401408 Hom.: 0 Cov.: 36 AF XY: 0.00 AC XY: 0 AN XY: 690760

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

African (AFR) AF: 0.00 AC: 0 AN: 32652

American (AMR) AF: 0.00 AC: 0 AN: 35982

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 23764

East Asian (EAS) AF: 0.00 AC: 0 AN: 38138

South Asian (SAS) AF: 0.00 AC: 0 AN: 78206

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 48304

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5580

European-Non Finnish (NFE) AF: 9.25e-7 AC: 1 AN: 1080712

Other (OTH) AF: 0.00 AC: 0 AN: 58070

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Brugada syndrome 8 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.083
BayesDel_addAF	Uncertain	0.065	T
BayesDel_noAF	Benign	-0.14
CADD	Benign	18
DANN	Uncertain	0.98
DEOGEN2	Benign	0.23	T
Eigen	Benign	-0.64
Eigen_PC	Benign	-0.62
FATHMM_MKL	Benign	0.051	N
LIST_S2	Benign	0.79	T
M_CAP	Pathogenic	0.69	D
MetaRNN	Benign	0.20	T
MetaSVM	Uncertain	0.63	D
MutationAssessor	Benign	0.69	N
PhyloP100		0.0030
PrimateAI	Pathogenic	0.83	D
PROVEAN	Benign	-0.83	N
REVEL	Uncertain	0.34
Sift	Uncertain	0.0030	D
Sift4G	Benign	0.21	T
Polyphen		0.0	B
Vest4		0.14
MutPred		0.21		Gain of relative solvent accessibility (P = 0.0215)
MVP		0.78
MPC		0.75
ClinPred		0.19	T
GERP RS		1.9
Varity_R		0.18
gMVP		0.27
Mutation Taster		=81/19	polymorphism

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

Other links and lift over

dbSNP: rs878854774; hg19: chr15-73615127;