rs1554040120

Variant names:

• chr5-45695679-TG-T
• rs1554040120
• NM_021072.4:c.414delC

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_021072.4(HCN1):​c.414delC​(p.Tyr138fs) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. Y138Y) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: HCN1 NM_021072.4 frameshift
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.19
• Publications: 0 publications found

Genes affected

HCN1 (HGNC:4845): (hyperpolarization activated cyclic nucleotide gated potassium channel 1) The membrane protein encoded by this gene is a hyperpolarization-activated cation channel that contributes to the native pacemaker currents in heart and neurons. The encoded protein can homodimerize or heterodimerize with other pore-forming subunits to form a potassium channel. This channel may act as a receptor for sour tastes. [provided by RefSeq, Oct 2011]

HCN1 Gene-Disease associations (from GenCC):

• developmental and epileptic encephalopathy, 24

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• generalized epilepsy with febrile seizures plus

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• generalized epilepsy with febrile seizures plus, type 10

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• undetermined early-onset epileptic encephalopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 5-45695679-TG-T is Pathogenic according to our data. Variant chr5-45695679-TG-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 496679.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HCN1	NM_021072.4	c.414delC	p.Tyr138fs	frameshift_variant	Exon 1 of 8	ENST00000303230.6	NP_066550.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HCN1	ENST00000303230.6	c.414delC	p.Tyr138fs	frameshift_variant	Exon 1 of 8	1	NM_021072.4	ENSP00000307342.4
HCN1	ENST00000673735.1	c.414delC	p.Tyr138fs	frameshift_variant	Exon 1 of 9			ENSP00000501107.1
HCN1	ENST00000634658.1	c.414delC	p.Tyr138fs	frameshift_variant	Exon 1 of 2	3		ENSP00000489134.1
HCN1	ENST00000638054.1	n.46delC		non_coding_transcript_exon_variant	Exon 1 of 2	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Developmental and epileptic encephalopathy, 24 Pathogenic:1

Jan 27, 2017

Equipe Genetique des Anomalies du Developpement, Université de Bourgogne

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		4.2

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1554040120; hg19: chr5-45695781;