15-73322875-G-C

Variant names:

• chr15-73322875-G-C
• rs982016034
• NM_005477.3:c.3218C>G

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_005477.3(HCN4):​c.3218C>G​(p.Pro1073Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000755 in 1,323,810 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: 7.6e-7 (0 hom.)
• Consequence: HCN4 NM_005477.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.11

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.33022344).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HCN4	NM_005477.3	c.3218C>G	p.Pro1073Arg	missense_variant	Exon 8 of 8	ENST00000261917.4	NP_005468.1
HCN4	XM_011521148.3	c.2000C>G	p.Pro667Arg	missense_variant	Exon 7 of 7		XP_011519450.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HCN4	ENST00000261917.4	c.3218C>G	p.Pro1073Arg	missense_variant	Exon 8 of 8	1	NM_005477.3	ENSP00000261917.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 7.55e-7 AC: 1 AN: 1323810 Hom.: 0 Cov.: 35 AF XY: 0.00 AC XY: 0 AN XY: 644806

Gnomad4 AFR exome AF: 0.0000331

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Brugada syndrome 8 Uncertain:1

Jul 20, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces proline, which is neutral and non-polar, with arginine, which is basic and polar, at codon 1073 of the HCN4 protein (p.Pro1073Arg). 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. 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. 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

Jan 10, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.P1073R variant (also known as c.3218C>G), located in coding exon 8 of the HCN4 gene, results from a C to G substitution at nucleotide position 3218. The proline at codon 1073 is replaced by arginine, an amino acid with dissimilar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Uncertain	0.074	D
BayesDel_noAF	Benign	-0.13
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.35	T
Eigen	Benign	-0.36
Eigen_PC	Benign	-0.30
FATHMM_MKL	Benign	0.72	D
LIST_S2	Benign	0.57	T
M_CAP	Pathogenic	0.88	D
MetaRNN	Benign	0.33	T
MetaSVM	Uncertain	0.24	D
MutationAssessor	Benign	1.0	L
PrimateAI	Pathogenic	0.88	D
PROVEAN	Benign	-0.89	N
REVEL	Benign	0.26
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.010	D
Polyphen		0.0060	B
Vest4		0.38
MutPred		0.27		Gain of MoRF binding (P = 0.0029);
MVP		0.83
MPC		0.73
ClinPred		0.62	D
GERP RS		2.8
Varity_R		0.082
gMVP		0.39

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

LitVar

Other links and lift over

dbSNP: rs982016034; hg19: chr15-73615216;