20-49373288-C-T

Variant summary

Our verdict is Benign. The variant received -8 ACMG points: 0P and 8B. BP4_ModerateBP6_ModerateBS2

The NM_004975.4(KCNB1):​c.2272G>A​(p.Ala758Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000752 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A758S) has been classified as Benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

KCNB1
NM_004975.4 missense

Scores

1
1
17

Clinical Significance

Benign criteria provided, single submitter B:1

Conservation

PhyloP100: 5.80

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -8 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.14093548).
BP6
Variant 20-49373288-C-T is Benign according to our data. Variant chr20-49373288-C-T is described in ClinVar as Benign. ClinVar VariationId is 567109.Status of the report is criteria_provided_single_submitter, 1 stars.
BS2
High AC in GnomAdExome4 at 11 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNB1NM_004975.4 linkc.2272G>A p.Ala758Thr missense_variant Exon 2 of 2 ENST00000371741.6 NP_004966.1 Q14721
KCNB1XM_011528799.3 linkc.2272G>A p.Ala758Thr missense_variant Exon 3 of 3 XP_011527101.1 Q14721
LOC105372649XR_001754659.2 linkn.1201+41264C>T intron_variant Intron 2 of 3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNB1ENST00000371741.6 linkc.2272G>A p.Ala758Thr missense_variant Exon 2 of 2 1 NM_004975.4 ENSP00000360806.3 Q14721

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251358
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000752
AC:
11
AN:
1461888
Hom.:
0
Cov.:
32
AF XY:
0.00000688
AC XY:
5
AN XY:
727246
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00000719
AC:
8
AN:
1112008
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.443
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Benign
Submissions summary: Benign:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy, 26 Benign:1
Nov 19, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.15
BayesDel_addAF
Benign
-0.071
T
BayesDel_noAF
Benign
-0.17
CADD
Benign
21
DANN
Benign
0.88
DEOGEN2
Benign
0.29
T;T
Eigen
Benign
-0.23
Eigen_PC
Benign
-0.018
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Benign
0.78
.;T
M_CAP
Benign
0.077
D
MetaRNN
Benign
0.14
T;T
MetaSVM
Uncertain
0.062
D
MutationAssessor
Benign
1.8
L;L
PhyloP100
5.8
PrimateAI
Benign
0.47
T
PROVEAN
Benign
-0.72
N;.
REVEL
Benign
0.22
Sift
Benign
0.70
T;.
Sift4G
Benign
0.50
T;T
Polyphen
0.0020
B;B
Vest4
0.061
MutPred
0.24
Loss of stability (P = 0.0511);Loss of stability (P = 0.0511);
MVP
0.51
MPC
0.18
ClinPred
0.15
T
GERP RS
4.8
Varity_R
0.054
gMVP
0.56
Mutation Taster
=56/44
polymorphism

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

Other links and lift over

dbSNP: rs774577428; hg19: chr20-47989825; COSMIC: COSV100870436; COSMIC: COSV100870436; API