rs1214997887

Positions:

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2PP2BP4_Moderate

The ENST00000371741.6(KCNB1):c.2200C>T(p.Pro734Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,928 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P734?) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

KCNB1
ENST00000371741.6 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.42

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:

(HGNC:):

links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

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=0.25944436).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein
KCNB1	NM_004975.4 linkuse as main transcript	c.2200C>T	p.Pro734Ser	missense_variant	2/2	ENST00000371741.6	NP_004966.1
LOC105372649	XR_001754659.2 linkuse as main transcript	n.1201+41336G>A		intron_variant, non_coding_transcript_variant
KCNB1	XM_011528799.3 linkuse as main transcript	c.2200C>T	p.Pro734Ser	missense_variant	3/3		XP_011527101.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris
KCNB1	ENST00000371741.6 linkuse as main transcript	c.2200C>T	p.Pro734Ser	missense_variant	2/2	1	NM_004975.4	ENSP00000360806	P1
KCNB1	ENST00000635465.1 linkuse as main transcript	c.2200C>T	p.Pro734Ser	missense_variant	3/3	1		ENSP00000489193	P1
	ENST00000637341.1 linkuse as main transcript	n.206+41336G>A		intron_variant, non_coding_transcript_variant		5
KCNB1	ENST00000635878.1 linkuse as main transcript	c.97-73977C>T		intron_variant		5		ENSP00000489908

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152040

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000242

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461888

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727246

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152040

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74276

show subpopulations

Gnomad4 AFR

AF:

0.0000242

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy, 26

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 26, 2017

In summary, this variant has uncertain impact on KCNB1 function. The available evidence is currently insufficient to determine its role in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C25"). This variant has not been reported in the literature in individuals with a KCNB1-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces proline with serine at codon 734 of the KCNB1 protein (p.Pro734Ser). The proline residue is highly conserved and there is a moderate physicochemical difference between proline and serine. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.13

BayesDel_addAF

Uncertain

0.14

BayesDel_noAF

Uncertain

-0.040

CADD

Benign

DANN

Benign

0.84

DEOGEN2

Benign

0.29

T;T

Eigen

Benign

0.13

Eigen_PC

Uncertain

0.23

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Benign

0.82

.;T

M_CAP

Uncertain

0.094

MetaRNN

Benign

0.26

T;T

MetaSVM

Uncertain

0.42

MutationAssessor

Benign

1.7

L;L

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.55

PROVEAN

Benign

-0.98

N;.

REVEL

Uncertain

0.40

Sift

Benign

0.74

T;.

Sift4G

Benign

0.68

T;T

Polyphen

0.63

P;P

Vest4

0.24

MutPred

0.27

Loss of catalytic residue at P734 (P = 0.0047);Loss of catalytic residue at P734 (P = 0.0047);

MVP

0.53

MPC

0.34

ClinPred

0.40

GERP RS

4.2

Varity_R

0.088

gMVP

0.56

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