rs149678923

Variant summary

Our verdict is Benign. The variant received -17 ACMG points: 0P and 17B. BP4_StrongBP6_Very_StrongBP7BS2

The NM_004975.4(KCNB1):​c.2106G>A​(p.Ala702Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000491 in 1,614,088 control chromosomes in the GnomAD database, including 4 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★).

Frequency

Genomes: 𝑓 0.0022 ( 2 hom., cov: 32)
Exomes 𝑓: 0.00031 ( 2 hom. )

Consequence

KCNB1
NM_004975.4 synonymous

Scores

2

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:4

Conservation

PhyloP100: -2.73

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 -17 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.64).
BP6
Variant 20-49373454-C-T is Benign according to our data. Variant chr20-49373454-C-T is described in ClinVar as Benign. ClinVar VariationId is 382943.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BP7
Synonymous conserved (PhyloP=-2.73 with no splicing effect.
BS2
High AC in GnomAd4 at 335 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNB1NM_004975.4 linkc.2106G>A p.Ala702Ala synonymous_variant Exon 2 of 2 ENST00000371741.6 NP_004966.1 Q14721
KCNB1XM_011528799.3 linkc.2106G>A p.Ala702Ala synonymous_variant Exon 3 of 3 XP_011527101.1 Q14721
LOC105372649XR_001754659.2 linkn.1201+41430C>T intron_variant Intron 2 of 3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNB1ENST00000371741.6 linkc.2106G>A p.Ala702Ala synonymous_variant Exon 2 of 2 1 NM_004975.4 ENSP00000360806.3 Q14721
KCNB1ENST00000635465.1 linkc.2106G>A p.Ala702Ala synonymous_variant Exon 3 of 3 1 ENSP00000489193.1 Q14721
KCNB1ENST00000635878.1 linkc.97-74071G>A intron_variant Intron 1 of 2 5 ENSP00000489908.1 A0A1B0GU02
ENSG00000290421ENST00000637341.1 linkn.206+41430C>T intron_variant Intron 2 of 7 5

Frequencies

GnomAD3 genomes
AF:
0.00219
AC:
333
AN:
152098
Hom.:
2
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00727
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000851
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000193
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000132
Gnomad OTH
AF:
0.00384
GnomAD2 exomes
AF:
0.000658
AC:
165
AN:
250862
AF XY:
0.000487
show subpopulations
Gnomad AFR exome
AF:
0.00735
Gnomad AMR exome
AF:
0.000578
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000490
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000883
Gnomad OTH exome
AF:
0.000816
GnomAD4 exome
AF:
0.000313
AC:
458
AN:
1461872
Hom.:
2
Cov.:
32
AF XY:
0.000267
AC XY:
194
AN XY:
727238
show subpopulations
African (AFR)
AF:
0.00899
AC:
301
AN:
33480
American (AMR)
AF:
0.000492
AC:
22
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.000756
AC:
30
AN:
39690
South Asian (SAS)
AF:
0.0000580
AC:
5
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00537
AC:
31
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000342
AC:
38
AN:
1112006
Other (OTH)
AF:
0.000513
AC:
31
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.494
Heterozygous variant carriers
0
30
60
91
121
151
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
20
40
60
80
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:
0.00220
AC:
335
AN:
152216
Hom.:
2
Cov.:
32
AF XY:
0.00210
AC XY:
156
AN XY:
74424
show subpopulations
African (AFR)
AF:
0.00730
AC:
303
AN:
41526
American (AMR)
AF:
0.000850
AC:
13
AN:
15300
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5180
South Asian (SAS)
AF:
0.000208
AC:
1
AN:
4816
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10602
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000132
AC:
9
AN:
68010
Other (OTH)
AF:
0.00380
AC:
8
AN:
2108
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.504
Heterozygous variant carriers
0
15
29
44
58
73
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
4
8
12
16
20
<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:
0.00131
Hom.:
0
Bravo
AF:
0.00232
Asia WGS
AF:
0.000289
AC:
1
AN:
3478
EpiCase
AF:
0.000109
EpiControl
AF:
0.000119

ClinVar

Significance: Benign
Submissions summary: Benign:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Benign:2
Jun 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

KCNB1: BP4, BP7, BS1, BS2 -

-
Breakthrough Genomics, Breakthrough Genomics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

not specified Benign:1
Aug 17, 2016
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Developmental and epileptic encephalopathy, 26 Benign:1
Jan 19, 2025
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
BayesDel_noAF
Benign
-0.64
CADD
Benign
0.59
DANN
Benign
0.61
PhyloP100
-2.7
Mutation Taster
=96/4
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: rs149678923; hg19: chr20-47989991; COSMIC: COSV65569043; COSMIC: COSV65569043; API