20-49373040-G-A

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.2520C>T​(p.Asp840Asp) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000192 in 1,613,966 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.00016 ( 1 hom., cov: 32)
Exomes 𝑓: 0.00020 ( 1 hom. )

Consequence

KCNB1
NM_004975.4 synonymous

Scores

2

Clinical Significance

Likely benign criteria provided, multiple submitters, no conflicts B:3

Conservation

PhyloP100: -1.00

Publications

0 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=-0.89).
BP6
Variant 20-49373040-G-A is Benign according to our data. Variant chr20-49373040-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 514758.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BP7
Synonymous conserved (PhyloP=-1 with no splicing effect.
BS2
High AC in GnomAd4 at 24 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNB1NM_004975.4 linkc.2520C>T p.Asp840Asp synonymous_variant Exon 2 of 2 ENST00000371741.6 NP_004966.1 Q14721
KCNB1XM_011528799.3 linkc.2520C>T p.Asp840Asp synonymous_variant Exon 3 of 3 XP_011527101.1 Q14721
LOC105372649XR_001754659.2 linkn.1201+41016G>A intron_variant Intron 2 of 3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNB1ENST00000371741.6 linkc.2520C>T p.Asp840Asp synonymous_variant Exon 2 of 2 1 NM_004975.4 ENSP00000360806.3 Q14721

Frequencies

GnomAD3 genomes
AF:
0.000158
AC:
24
AN:
152130
Hom.:
1
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000966
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00519
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.000479
GnomAD2 exomes
AF:
0.000231
AC:
58
AN:
251314
AF XY:
0.000206
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00427
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000114
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.000196
AC:
286
AN:
1461836
Hom.:
1
Cov.:
32
AF XY:
0.000212
AC XY:
154
AN XY:
727216
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00452
AC:
118
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5754
European-Non Finnish (NFE)
AF:
0.000138
AC:
154
AN:
1111988
Other (OTH)
AF:
0.000215
AC:
13
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.477
Heterozygous variant carriers
0
15
30
45
60
75
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.000158
AC:
24
AN:
152130
Hom.:
1
Cov.:
32
AF XY:
0.000135
AC XY:
10
AN XY:
74314
show subpopulations
African (AFR)
AF:
0.0000966
AC:
4
AN:
41420
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00519
AC:
18
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10606
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68014
Other (OTH)
AF:
0.000479
AC:
1
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.516
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
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
Alfa
AF:
0.000510
Hom.:
0
Bravo
AF:
0.000144
Asia WGS
AF:
0.000289
AC:
1
AN:
3478
EpiCase
AF:
0.000164
EpiControl
AF:
0.000178

ClinVar

Significance: Likely benign
Submissions summary: Benign:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Benign:2
Jul 14, 2020
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

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

- -

Developmental and epileptic encephalopathy, 26 Benign:1
Nov 15, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely 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
-0.89
CADD
Benign
0.010
DANN
Benign
0.42
PhyloP100
-1.0
Mutation Taster
=100/0
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: rs372147544; hg19: chr20-47989577; COSMIC: COSV106531881; COSMIC: COSV106531881; API