Genetic Variant HCN4:p.Gln199His (chr15-73367674-C-G) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_005477.3(HCN4):c.597G>C(p.Gln199His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000689 in 1,452,318 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

HCN4
NM_005477.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.07

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 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 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.597G>C	p.Gln199His	missense_variant	Exon 1 of 8	ENST00000261917.4	NP_005468.1	Q9Y3Q4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HCN4	ENST00000261917.4 link	c.597G>C	p.Gln199His	missense_variant	Exon 1 of 8	1	NM_005477.3	ENSP00000261917.3		Q9Y3Q4

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000430

AC:

AN:

232552

Hom.:

AF XY:

0.00000775

AC XY:

AN XY:

128978

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000568

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

6.89e-7

AC:

AN:

1452318

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

722792

show subpopulations

Gnomad4 AFR exome

AF:

0.00

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:

0.0000166

GnomAD4 genome

Cov.:

Bravo

AF:

0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Cardiovascular phenotype

Uncertain:1

Mar 24, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Q199H variant (also known as c.597G>C), located in coding exon 1 of the HCN4 gene, results from a G to C substitution at nucleotide position 597. The glutamine at codon 199 is replaced by histidine, an amino acid with highly similar properties. 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

Benign

0.21

BayesDel_addAF

Benign

-0.021

BayesDel_noAF

Benign

-0.10

CADD

Benign

DANN

Uncertain

0.99

DEOGEN2

Benign

0.38

Eigen

Benign

0.0082

Eigen_PC

Benign

-0.036

FATHMM_MKL

Uncertain

0.87

LIST_S2

Benign

0.43

M_CAP

Pathogenic

0.54

MetaRNN

Uncertain

0.56

MetaSVM

Pathogenic

0.81

MutationAssessor

Benign

1.8

PrimateAI

Pathogenic

0.79

PROVEAN

Benign

-1.5

REVEL

Uncertain

0.52

Sift

Uncertain

0.027

Sift4G

Uncertain

0.0060

Polyphen

0.98

Vest4

0.39

MutPred

0.26

Loss of loop (P = 0.0374);

MVP

0.96

MPC

1.0

ClinPred

0.43

GERP RS

2.3

Varity_R

0.088

gMVP

0.65

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over