20-49373236-G-C

Position:

chr20-49373236-G-C

Variant summary

Our verdict is Benign. Variant got -10 ACMG points: 1P and 11B. PP2BP4_ModerateBP6BS1BS2

The NM_004975.4(KCNB1):c.2324C>G(p.Pro775Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000366 in 1,614,124 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000037 ( 0 hom. )

Consequence

KCNB1
NM_004975.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:4

Conservation

PhyloP100: 9.45

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 links:

ENSG00000290421 (HGNC:):

ENSG00000290421 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -10 ACMG points.

PP2

Missense variant in gene, where missense usually causes diseases (based on misZ statistic), KCNB1. . Gene score misZ 4.269 (greater than the threshold 3.09). Trascript score misZ 5.3923 (greater than threshold 3.09). GenCC has associacion of gene with undetermined early-onset epileptic encephalopathy, complex neurodevelopmental disorder, developmental and epileptic encephalopathy, 26.

BP4

Computational evidence support a benign effect (MetaRNN=0.12827235).

BP6

Variant 20-49373236-G-C is Benign according to our data. Variant chr20-49373236-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 425270.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=1}.

BS1

Variant frequency is greater than expected in population mid. gnomad4_exome allele frequency = 0.0000369 (54/1461888) while in subpopulation MID AF= 0.000693 (4/5768). AF 95% confidence interval is 0.000236. There are 0 homozygotes in gnomad4_exome. There are 35 alleles in male gnomad4_exome subpopulation. Median coverage is 32. This position pass quality control queck.

BS2

High AC in GnomAd4 at 5 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNB1	NM_004975.4 linkuse as main transcript	c.2324C>G	p.Pro775Arg	missense_variant	2/2	ENST00000371741.6	NP_004966.1	Q14721
KCNB1	XM_011528799.3 linkuse as main transcript	c.2324C>G	p.Pro775Arg	missense_variant	3/3		XP_011527101.1	Q14721
LOC105372649	XR_001754659.2 linkuse as main transcript	n.1201+41212G>C		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	UniProt
KCNB1	ENST00000371741.6 linkuse as main transcript	c.2324C>G	p.Pro775Arg	missense_variant	2/2	1	NM_004975.4	ENSP00000360806.3	Q14721
KCNB1	ENST00000635465.1 linkuse as main transcript	c.2324C>G	p.Pro775Arg	missense_variant	3/3	1		ENSP00000489193.1	Q14721
KCNB1	ENST00000635878.1 linkuse as main transcript	c.97-73853C>G		intron_variant		5		ENSP00000489908.1	A0A1B0GU02
ENSG00000290421	ENST00000637341.1 linkuse as main transcript	n.206+41212G>C		intron_variant		5

Frequencies

GnomAD3 genomes

AF:

0.0000329

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:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.000479

GnomAD3 exomes

AF:

0.0000358

AC:

AN:

251358

Hom.:

AF XY:

0.0000589

AC XY:

AN XY:

135840

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:

0.000229

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000369

AC:

AN:

1461888

Hom.:

Cov.:

AF XY:

0.0000481

AC XY:

AN XY:

727242

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000220

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000270

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000328

AC:

AN:

152236

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74426

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000208

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.000474

Alfa

AF:

0.0000364

Hom.:

Bravo

AF:

0.0000416

ExAC

AF:

0.0000412

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:4

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Oct 01, 2016	- -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	May 05, 2020	- -

Developmental and epileptic encephalopathy, 26

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 27, 2023

- -

KCNB1-related disorder

Benign:1

Likely benign, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Feb 21, 2019

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

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 27, 2024

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

0.081

BayesDel_addAF

Benign

-0.022

BayesDel_noAF

Uncertain

0.020

CADD

Benign

DANN

Benign

0.97

DEOGEN2

Benign

0.26

T;T

Eigen

Uncertain

0.32

Eigen_PC

Uncertain

0.43

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Benign

0.77

.;T

M_CAP

Benign

0.063

MetaRNN

Benign

0.13

T;T

MetaSVM

Uncertain

0.076

MutationAssessor

Benign

0.69

N;N

PrimateAI

Benign

0.46

PROVEAN

Benign

-0.43

N;.

REVEL

Uncertain

0.42

Sift

Benign

0.15

T;.

Sift4G

Benign

0.55

T;T

Polyphen

0.54

P;P

Vest4

0.37

MutPred

0.14

Loss of glycosylation at P775 (P = 0.0076);Loss of glycosylation at P775 (P = 0.0076);

MVP

0.58

MPC

0.21

ClinPred

0.18

GERP RS

4.6

Varity_R

0.10

gMVP

0.38

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