chr20-49374997-G-A

Variant summary

Our verdict is Benign. The variant received -16 ACMG points: 0P and 16B. BP4_StrongBP6_Very_StrongBS2

The NM_004975.4(KCNB1):​c.568-5C>T variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000059 in 1,541,388 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000060 ( 0 hom. )

Consequence

KCNB1
NM_004975.4 splice_region, intron

Scores

2
Splicing: ADA: 0.00004545
2

Clinical Significance

Likely benign criteria provided, multiple submitters, no conflicts B:4

Conservation

PhyloP100: 1.94

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: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
  • 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 -16 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.68).
BP6
Variant 20-49374997-G-A is Benign according to our data. Variant chr20-49374997-G-A is described in ClinVar as Likely_benign. ClinVar VariationId is 542058.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS2
High AC in GnomAd4 at 8 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

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNB1
NM_004975.4
MANE Select
c.568-5C>T
splice_region intron
N/ANP_004966.1Q14721

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNB1
ENST00000371741.6
TSL:1 MANE Select
c.568-5C>T
splice_region intron
N/AENSP00000360806.3Q14721
KCNB1
ENST00000635465.1
TSL:1
c.568-5C>T
splice_region intron
N/AENSP00000489193.1Q14721
KCNB1
ENST00000635878.1
TSL:5
c.97-75614C>T
intron
N/AENSP00000489908.1A0A1B0GU02

Frequencies

GnomAD3 genomes
AF:
0.0000526
AC:
8
AN:
152184
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000262
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:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000128
AC:
25
AN:
195264
AF XY:
0.000136
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000336
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000134
Gnomad OTH exome
AF:
0.000860
GnomAD4 exome
AF:
0.0000598
AC:
83
AN:
1389086
Hom.:
0
Cov.:
29
AF XY:
0.0000659
AC XY:
45
AN XY:
682360
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
31494
American (AMR)
AF:
0.000358
AC:
13
AN:
36342
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
21610
East Asian (EAS)
AF:
0.00
AC:
0
AN:
38952
South Asian (SAS)
AF:
0.00
AC:
0
AN:
74542
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
50790
Middle Eastern (MID)
AF:
0.000370
AC:
2
AN:
5408
European-Non Finnish (NFE)
AF:
0.0000615
AC:
66
AN:
1072790
Other (OTH)
AF:
0.0000350
AC:
2
AN:
57158
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.486
Heterozygous variant carriers
0
5
10
14
19
24
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
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
GnomAD4 genome
AF:
0.0000525
AC:
8
AN:
152302
Hom.:
0
Cov.:
32
AF XY:
0.0000671
AC XY:
5
AN XY:
74470
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41552
American (AMR)
AF:
0.000261
AC:
4
AN:
15306
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.481
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

Genome 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
Alfa
AF:
0.0000712
Hom.:
0
Bravo
AF:
0.0000680

ClinVar

ClinVar submissions
Significance:Likely benign
Revision:criteria provided, multiple submitters, no conflicts
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
-
2
not provided (2)
-
-
1
Developmental and epileptic encephalopathy, 26 (1)
-
-
1
Inborn genetic diseases (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.68
CADD
Benign
12
DANN
Benign
0.57
PhyloP100
1.9
Mutation Taster
=99/1
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.000045
dbscSNV1_RF
Benign
0.0
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: rs185995580; hg19: chr20-47991534; API