rs1555477316

Variant names:

• chr15-73343606-G-A
• rs1555477316
• NM_005477.3:c.988C>T

Your query was ambiguous. Multiple possible variants found:

• chr15-73343606-G-A
• chr15-73343606-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_005477.3(HCN4):​c.988C>T​(p.Pro330Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 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. P330L) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: HCN4 NM_005477.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.87
• 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: 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

LOC105370890 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.908

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HCN4	NM_005477.3	c.988C>T	p.Pro330Ser	missense_variant	Exon 2 of 8	ENST00000261917.4	NP_005468.1
LOC105370890	NR_188273.1	n.788+24G>A		intron_variant	Intron 5 of 5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HCN4	ENST00000261917.4	c.988C>T	p.Pro330Ser	missense_variant	Exon 2 of 8	1	NM_005477.3	ENSP00000261917.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Brugada syndrome 8 Uncertain:1

Dec 18, 2018

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature in individuals with HCN4-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces proline with serine at codon 330 of the HCN4 protein (p.Pro330Ser). The proline residue is highly conserved and there is a moderate physicochemical difference between proline and serine. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.43
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.89	D
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.89
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Uncertain	0.28	D
MetaRNN	Pathogenic	0.91	D
MetaSVM	Pathogenic	0.99	D
MutationAssessor	Uncertain	2.4	M
PhyloP100		9.9
PrimateAI	Pathogenic	0.81	D
PROVEAN	Pathogenic	-7.7	D
REVEL	Pathogenic	0.87
Sift	Uncertain	0.0060	D
Sift4G	Uncertain	0.0020	D
Polyphen		1.0	D
Vest4		0.82
MutPred		0.60		Gain of MoRF binding (P = 0.0638);
MVP		1.0
MPC		1.1
ClinPred		1.0	D
GERP RS		5.3
Varity_R		0.83
gMVP		0.90
Mutation Taster		=18/82	disease causing

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: rs1555477316; hg19: chr15-73635947;