20-49373236-G-T

Variant names:

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_ModerateBP6BS2

The NM_004975.4(KCNB1):c.2324C>A(p.Pro775His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000991 in 1,614,006 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P775A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000099 ( 1 hom. )

Consequence

KCNB1
NM_004975.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:1

Conservation

PhyloP100: 9.45

Publications

1 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 -7 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.15990713).

BP6

Variant 20-49373236-G-T is Benign according to our data. Variant chr20-49373236-G-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 430040.

BS2

High AC in GnomAd4 at 16 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004975.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNB1	NM_004975.4	MANE Select	c.2324C>A	p.Pro775His	missense	Exon 2 of 2	NP_004966.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
KCNB1	ENST00000371741.6	TSL:1 MANE Select	c.2324C>A	p.Pro775His	missense	Exon 2 of 2	ENSP00000360806.3
KCNB1	ENST00000635465.1	TSL:1	c.2324C>A	p.Pro775His	missense	Exon 3 of 3	ENSP00000489193.1
KCNB1	ENST00000635878.1	TSL:5	c.97-73853C>A		intron	N/A	ENSP00000489908.1

Frequencies

GnomAD3 genomes

AF:

0.000105

AC:

AN:

152118

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000206

Gnomad OTH

AF:

0.000479

GnomAD2 exomes

AF:

0.0000477

AC:

AN:

251358

AF XY:

0.0000442

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000792

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000985

AC:

144

AN:

1461888

Hom.:

Cov.:

AF XY:

0.000109

AC XY:

AN XY:

727242

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33480

American (AMR)

AF:

0.0000447

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000504

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000464

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.000108

AC:

120

AN:

1112006

Other (OTH)

AF:

0.000248

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.488

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

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

GnomAD4 genome

AF:

0.000105

AC:

AN:

152118

Hom.:

Cov.:

AF XY:

0.000121

AC XY:

AN XY:

74298

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41422

American (AMR)

AF:

0.00

AC:

AN:

15276

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5194

South Asian (SAS)

AF:

0.00

AC:

AN:

4822

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10604

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000206

AC:

AN:

68016

Other (OTH)

AF:

0.000479

AC:

AN:

2086

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.438

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:

0.000109

Hom.:

Bravo

AF:

0.0000529

ExAC

AF:

0.0000330

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.000164

EpiControl

AF:

0.000119

ClinVar

ClinVar submissions as Germline

Significance:Conflicting classifications of pathogenicity

Revision:criteria provided, conflicting classifications

View on ClinVar

Pathogenic

VUS

Benign

Condition

not provided (2)

Developmental and epileptic encephalopathy, 26 (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.086

BayesDel_addAF

Benign

-0.086

BayesDel_noAF

Uncertain

0.0

CADD

Uncertain

(source)

DANN

Uncertain

0.99

DEOGEN2

Benign

0.29

Eigen

Benign

0.15

Eigen_PC

Uncertain

0.31

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Benign

0.72

M_CAP

Benign

0.048

MetaRNN

Benign

0.16

MetaSVM

Uncertain

-0.013

MutationAssessor

Benign

0.69

PhyloP100

9.4

PrimateAI

Benign

0.45

PROVEAN

Benign

-0.74

REVEL

Uncertain

0.38

Sift

Benign

0.043

Sift4G

Benign

0.25

Polyphen

0.016

Vest4

0.34

MutPred

0.097

Loss of glycosylation at P775 (P = 0.0076)

MVP

0.50

MPC

0.37

ClinPred

0.17

GERP RS

4.6

Varity_R

0.12

gMVP

0.31

Mutation Taster

=81/19

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

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

ClinVar submissions as Germline

Computational scores

Splicing

Publications

Other links and lift over