rs587777492
Variant summary
Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM2PP3PP5_Very_Strong
The NM_021072.4(HCN1):c.299C>T(p.Ser100Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,459,034 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S100A) has been classified as Likely benign.
Frequency
Consequence
NM_021072.4 missense
Scores
Clinical Significance
Conservation
Publications
- developmental and epileptic encephalopathy, 24Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
- generalized epilepsy with febrile seizures plusInheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
- generalized epilepsy with febrile seizures plus, type 10Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- undetermined early-onset epileptic encephalopathyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Pathogenic. The variant received 11 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| HCN1 | NM_021072.4 | c.299C>T | p.Ser100Phe | missense_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.299C>T | p.Ser100Phe | missense_variant | Exon 1 of 8 | 1 | NM_021072.4 | ENSP00000307342.4 | ||
| HCN1 | ENST00000673735.1 | c.299C>T | p.Ser100Phe | missense_variant | Exon 1 of 9 | ENSP00000501107.1 | ||||
| HCN1 | ENST00000634658.1 | c.299C>T | p.Ser100Phe | missense_variant | Exon 1 of 2 | 3 | ENSP00000489134.1 | |||
| HCN1 | ENST00000638054.1 | n.-70C>T | upstream_gene_variant | 5 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome AF: 6.85e-7 AC: 1AN: 1459034Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 725952 show subpopulations ⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
Age Distribution
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Developmental and epileptic encephalopathy Pathogenic:1
This sequence change replaces serine, which is neutral and polar, with phenylalanine, which is neutral and non-polar, at codon 100 of the HCN1 protein (p.Ser100Phe). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with early infantile epileptic encephalopathy (PMID: 24747641). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 139572). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt HCN1 protein function with a negative predictive value of 80%. Experimental studies have shown that this missense change affects HCN1 function (PMID: 24747641). For these reasons, this variant has been classified as Pathogenic. -
Developmental and epileptic encephalopathy, 24 Pathogenic:1
- -
Generalized epilepsy with febrile seizures plus, type 10 Pathogenic:1
Criteria applied: PS2_MOD,PS4_MOD,PS3_SUP,PM2_SUP,PP2,PP3 -
not provided Pathogenic:1
Published functional studies suggest this variant results in impairment of protein function, however additional studies are needed to validate the functional effect of this variant (PMID: 24747641, 26030105, 34310985); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 26030105, 34310985, 24747641, 35845605, 35359639) -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at