20-49373236-G-A

Variant summary

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

The NM_004975.4(KCNB1):​c.2324C>T​(p.Pro775Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000496 in 1,614,006 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 Likely benign (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P775A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

KCNB1
NM_004975.4 missense

Scores

1
6
11

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: 9.45

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=0.16978109).
BP6
Variant 20-49373236-G-A is Benign according to our data. Variant chr20-49373236-G-A is described in ClinVar as Likely_benign. ClinVar VariationId is 1961886.Status of the report is criteria_provided_single_submitter, 1 stars.
BS2
High AC in GnomAdExome4 at 7 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004975.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNB1
NM_004975.4
MANE Select
c.2324C>Tp.Pro775Leu
missense
Exon 2 of 2NP_004966.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNB1
ENST00000371741.6
TSL:1 MANE Select
c.2324C>Tp.Pro775Leu
missense
Exon 2 of 2ENSP00000360806.3
KCNB1
ENST00000635465.1
TSL:1
c.2324C>Tp.Pro775Leu
missense
Exon 3 of 3ENSP00000489193.1
KCNB1
ENST00000635878.1
TSL:5
c.97-73853C>T
intron
N/AENSP00000489908.1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152118
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251358
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000479
AC:
7
AN:
1461888
Hom.:
0
Cov.:
32
AF XY:
0.00000688
AC XY:
5
AN XY:
727242
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000447
AC:
2
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:
5768
European-Non Finnish (NFE)
AF:
0.00000270
AC:
3
AN:
1112006
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.461
Heterozygous variant carriers
0
1
2
2
3
4
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
AF:
0.00000657
AC:
1
AN:
152118
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74298
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41422
American (AMR)
AF:
0.0000655
AC:
1
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68016
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000364
Hom.:
0
ExAC
AF:
0.00000824
AC:
1

ClinVar

ClinVar submissions as Germline

Significance:Likely benign
Revision:criteria provided, single submitter
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
-
1
Developmental and epileptic encephalopathy, 26 (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.080
BayesDel_addAF
Uncertain
0.099
D
BayesDel_noAF
Uncertain
0.0
CADD
Benign
23
DANN
Uncertain
0.99
DEOGEN2
Benign
0.36
T
Eigen
Benign
0.15
Eigen_PC
Uncertain
0.30
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Benign
0.85
T
M_CAP
Benign
0.036
D
MetaRNN
Benign
0.17
T
MetaSVM
Uncertain
-0.23
T
MutationAssessor
Benign
0.69
N
PhyloP100
9.4
PrimateAI
Benign
0.47
T
PROVEAN
Benign
-1.4
N
REVEL
Uncertain
0.34
Sift
Benign
0.050
D
Sift4G
Benign
0.27
T
Polyphen
0.0070
B
Vest4
0.28
MutPred
0.12
Loss of glycosylation at P775 (P = 0.0076)
MVP
0.67
MPC
0.20
ClinPred
0.54
D
GERP RS
4.6
Varity_R
0.093
gMVP
0.40
Mutation Taster
=83/17
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: rs530927636; hg19: chr20-47989773; API