20-49374193-C-T

Variant names:

Variant summary

Our verdict is Benign. The variant received -14 ACMG points: 0P and 14B. BP4_ModerateBP6_Very_StrongBS2

The NM_004975.4(KCNB1):c.1367G>A(p.Arg456Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000216 in 1,614,042 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R456G) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00023 ( 0 hom. )

Consequence

KCNB1
NM_004975.4 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:5

Conservation

PhyloP100: 3.39

Publications

0 publications found

Variant links:

Genes affected

KCNB1 (HGNC:6231): (potassium voltage-gated channel subfamily B member 1) Voltage-gated potassium (Kv) channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. Four sequence-related potassium channel genes - shaker, shaw, shab, and shal - have been identified in Drosophila, and each has been shown to have human homolog(s). This gene encodes a member of the potassium channel, voltage-gated, shab-related subfamily. This member is a delayed rectifier potassium channel and its activity is modulated by some other family members. [provided by RefSeq, Jul 2008]

KCNB1 Gene-Disease associations (from GenCC):

complex neurodevelopmental disorder
Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
developmental and epileptic encephalopathy, 26
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
undetermined early-onset epileptic encephalopathy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

KCNB1 links:

ENSG00000290421 (HGNC:):

ENSG00000290421 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -14 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.23682433).

BP6

Variant 20-49374193-C-T is Benign according to our data. Variant chr20-49374193-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 385978.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BS2

High AC in GnomAd4 at 17 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNB1	NM_004975.4 link	c.1367G>A	p.Arg456Gln	missense_variant	Exon 2 of 2	ENST00000371741.6	NP_004966.1	Q14721
KCNB1	XM_011528799.3 link	c.1367G>A	p.Arg456Gln	missense_variant	Exon 3 of 3		XP_011527101.1	Q14721
LOC105372649	XR_001754659.2 link	n.1201+42169C>T		intron_variant	Intron 2 of 3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
KCNB1	ENST00000371741.6 link	c.1367G>A	p.Arg456Gln	missense_variant	Exon 2 of 2	1	NM_004975.4	ENSP00000360806.3	Q14721
KCNB1	ENST00000635465.1 link	c.1367G>A	p.Arg456Gln	missense_variant	Exon 3 of 3	1		ENSP00000489193.1	Q14721
KCNB1	ENST00000635878.1 link	c.97-74810G>A		intron_variant	Intron 1 of 2	5		ENSP00000489908.1	A0A1B0GU02
ENSG00000290421	ENST00000637341.1 link	n.206+42169C>T		intron_variant	Intron 2 of 7	5

Frequencies

GnomAD3 genomes

AF:

0.000112

AC:

AN:

152192

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00219

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000192

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000191

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000115

AC:

AN:

251384

AF XY:

0.000118

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000246

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000226

AC:

331

AN:

1461850

Hom.:

Cov.:

AF XY:

0.000228

AC XY:

166

AN XY:

727222

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000348

AC:

AN:

86250

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53402

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.000288

AC:

320

AN:

1111996

Other (OTH)

AF:

0.000132

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.488

Heterozygous variant carriers

112

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

100

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.000112

AC:

AN:

152192

Hom.:

Cov.:

AF XY:

0.0000807

AC XY:

AN XY:

74350

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41422

American (AMR)

AF:

0.00

AC:

AN:

15290

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.000192

AC:

AN:

5200

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10618

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000191

AC:

AN:

68044

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.484

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000392

Hom.:

Bravo

AF:

0.000147

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000778

AC:

ExAC

AF:

0.0000906

AC:

EpiCase

AF:

0.000164

EpiControl

AF:

0.000237

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Benign:2

Oct 01, 2023

CeGaT Center for Human Genetics Tuebingen

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

KCNB1: BP5, BS1:Supporting -

Jun 02, 2021

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Developmental and epileptic encephalopathy, 26

Benign:1

Dec 15, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

KCNB1-related disorder

Benign:1

Nov 21, 2023

PreventionGenetics, part of Exact Sciences

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Inborn genetic diseases

Benign:1

Oct 20, 2023

Ambry Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.14

BayesDel_addAF

Uncertain

0.066

BayesDel_noAF

Pathogenic

0.15

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.39

T;T

Eigen

Pathogenic

0.69

Eigen_PC

Pathogenic

0.70

FATHMM_MKL

Uncertain

0.94

LIST_S2

Pathogenic

0.98

.;D

M_CAP

Uncertain

0.20

MetaRNN

Benign

0.24

T;T

MetaSVM

Pathogenic

0.96

MutationAssessor

Uncertain

2.3

M;M

PhyloP100

3.4

PrimateAI

Benign

0.46

PROVEAN

Benign

-2.3

N;.

REVEL

Uncertain

0.57

Sift

Benign

0.041

D;.

Sift4G

Uncertain

0.024

D;D

Polyphen

1.0

D;D

Vest4

0.17

MVP

0.84

MPC

0.74

ClinPred

0.29

GERP RS

5.8

Varity_R

0.29

gMVP

0.78

Mutation Taster

=68/32

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over