rs531563186

Positions:

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 1P and 6B. PP2BP4BS1_SupportingBS2

The NM_001112741.2(KCNC1):c.1657G>A(p.Glu553Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000368 in 1,550,646 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign 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. E553D) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000039 ( 1 hom. )

Consequence

KCNC1
NM_001112741.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 7.73

Variant links:

Genes affected

KCNC1 (HGNC:6233): (potassium voltage-gated channel subfamily C member 1) This gene encodes a member of a family of integral membrane proteins that mediate the voltage-dependent potassium ion permeability of excitable membranes. Alternative splicing is thought to result in two transcript variants encoding isoforms that differ at their C-termini. These isoforms have had conflicting names in the literature: the longer isoform has been called both "b" and "alpha", while the shorter isoform has been called both "a" and "beta" (PMIDs 1432046, 12091563). [provided by RefSeq, Oct 2014]

KCNC1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -5 ACMG points.

PP2

Missense variant in gene, where missense usually causes diseases (based on misZ statistic), KCNC1. . Gene score misZ 4.5189 (greater than the threshold 3.09). Trascript score misZ 5.1707 (greater than threshold 3.09). GenCC has associacion of gene with progressive myoclonic epilepsy type 7, progressive myoclonus epilepsy, complex neurodevelopmental disorder.

BP4

Computational evidence support a benign effect (MetaRNN=0.32522547).

BS1

Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.0000131 (2/152216) while in subpopulation SAS AF= 0.000414 (2/4832). AF 95% confidence interval is 0.0000729. There are 0 homozygotes in gnomad4. There are 2 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

BS2

High AC in GnomAdExome4 at 55 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNC1	NM_001112741.2 linkuse as main transcript	c.1657G>A	p.Glu553Lys	missense_variant	3/4	ENST00000265969.8	NP_001106212.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNC1	ENST00000265969.8 linkuse as main transcript	c.1657G>A	p.Glu553Lys	missense_variant	3/4	5	NM_001112741.2	ENSP00000265969	P1	P48547-2

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152216

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000414

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000111

AC:

AN:

153158

Hom.:

AF XY:

0.000172

AC XY:

AN XY:

81274

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000705

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000169

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000393

AC:

AN:

1398430

Hom.:

Cov.:

AF XY:

0.0000594

AC XY:

AN XY:

689766

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000841

Gnomad4 SAS exome

AF:

0.000619

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000185

Gnomad4 OTH exome

AF:

0.0000173

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152216

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74358

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000414

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

ExAC

AF:

0.000223

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Progressive myoclonic epilepsy type 7

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 27, 2023

This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 553 of the KCNC1 protein (p.Glu553Lys). This variant is present in population databases (rs531563186, gnomAD 0.07%), and has an allele count higher than expected for a pathogenic variant. This variant has not been reported in the literature in individuals affected with KCNC1-related conditions. ClinVar contains an entry for this variant (Variation ID: 586093). 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 expected to disrupt KCNC1 protein function with a positive predictive value of 95%. 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. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

May 31, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Benign

-0.018

BayesDel_noAF

Uncertain

0.11

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Uncertain

0.42

Eigen_PC

Uncertain

0.49

FATHMM_MKL

Uncertain

0.97

LIST_S2

Uncertain

0.97

M_CAP

Uncertain

0.23

MetaRNN

Benign

0.33

MetaSVM

Pathogenic

1.1

MutationTaster

Benign

0.89

PrimateAI

Uncertain

0.77

PROVEAN

Benign

-1.5

REVEL

Pathogenic

0.73

Sift

Uncertain

0.0040

Sift4G

Uncertain

0.011

Vest4

0.57

MutPred

0.39

Gain of ubiquitination at E553 (P = 0.017);

MVP

0.87

MPC

1.9

ClinPred

0.31

GERP RS

4.8

gMVP

0.61

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