NM_004975.4:c.177G>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.177G>A​(p.Lys59Lys) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000349 in 1,609,492 control chromosomes in the GnomAD database, including 8 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.00049 ( 2 hom., cov: 32)
Exomes 𝑓: 0.00033 ( 6 hom. )

Consequence

KCNB1
NM_004975.4 synonymous

Scores

2

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:3

Conservation

PhyloP100: 0.167

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=-0.49).
BP6
Variant 20-49482304-C-T is Benign according to our data. Variant chr20-49482304-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 383991.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BP7
Synonymous conserved (PhyloP=0.167 with no splicing effect.
BS2
High AC in GnomAd4 at 75 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNB1NM_004975.4 linkc.177G>A p.Lys59Lys synonymous_variant Exon 1 of 2 ENST00000371741.6 NP_004966.1 Q14721
KCNB1XM_011528799.3 linkc.177G>A p.Lys59Lys synonymous_variant Exon 2 of 3 XP_011527101.1 Q14721

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNB1ENST00000371741.6 linkc.177G>A p.Lys59Lys synonymous_variant Exon 1 of 2 1 NM_004975.4 ENSP00000360806.3 Q14721
KCNB1ENST00000635465.1 linkc.177G>A p.Lys59Lys synonymous_variant Exon 2 of 3 1 ENSP00000489193.1 Q14721

Frequencies

GnomAD3 genomes
AF:
0.000486
AC:
74
AN:
152236
Hom.:
2
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000482
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000196
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.0129
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.00110
AC:
265
AN:
241926
AF XY:
0.00104
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000585
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0143
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.000848
GnomAD4 exome
AF:
0.000334
AC:
486
AN:
1457138
Hom.:
6
Cov.:
31
AF XY:
0.000329
AC XY:
238
AN XY:
724318
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33402
American (AMR)
AF:
0.0000673
AC:
3
AN:
44564
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26046
East Asian (EAS)
AF:
0.0110
AC:
437
AN:
39562
South Asian (SAS)
AF:
0.0000349
AC:
3
AN:
85992
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52068
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5718
European-Non Finnish (NFE)
AF:
0.00000360
AC:
4
AN:
1109662
Other (OTH)
AF:
0.000649
AC:
39
AN:
60124
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.501
Heterozygous variant carriers
0
35
70
105
140
175
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
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:
0.000492
AC:
75
AN:
152354
Hom.:
2
Cov.:
32
AF XY:
0.000483
AC XY:
36
AN XY:
74510
show subpopulations
African (AFR)
AF:
0.0000481
AC:
2
AN:
41584
American (AMR)
AF:
0.000196
AC:
3
AN:
15312
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.0129
AC:
67
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68022
Other (OTH)
AF:
0.000945
AC:
2
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.480
Heterozygous variant carriers
0
4
8
11
15
19
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:
0.000101
Hom.:
0
Bravo
AF:
0.000536
Asia WGS
AF:
0.00260
AC:
9
AN:
3478

ClinVar

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

Submissions by phenotype

not specified Benign:1
Dec 06, 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 22, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Benign:1
May 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 -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.49
CADD
Benign
10
DANN
Benign
0.64
PhyloP100
0.17
PromoterAI
-0.0078
Neutral
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: rs117017889; hg19: chr20-48098841; API