rs753401695

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4BS2

The NM_020822.3(KCNT1):​c.2020A>G​(p.Met674Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000804 in 1,404,968 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000088 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 missense

Scores

1
1
16

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 9.03

Publications

1 publications found
Variant links:
Genes affected
KCNT1 (HGNC:18865): (potassium sodium-activated channel subfamily T member 1) Potassium 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. This gene encodes a sodium-activated potassium channel subunit which is thought to function in ion conductance and developmental signaling pathways. Mutations in this gene cause the early-onset epileptic disorders, malignant migrating partial seizures of infancy and autosomal dominant nocturnal frontal lobe epilepsy. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2012]
KCNT1 Gene-Disease associations (from GenCC):
  • childhood-onset epilepsy syndrome
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • developmental and epileptic encephalopathy, 14
    Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
  • malignant migrating partial seizures of infancy
    Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Orphanet
  • autosomal dominant nocturnal frontal lobe epilepsy 5
    Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • autosomal dominant nocturnal frontal lobe epilepsy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -5 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.2931692).
BS2
High AC in GnomAdExome4 at 110 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_020822.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNT1
NM_020822.3
MANE Select
c.2020A>Gp.Met674Val
missense
Exon 19 of 31NP_065873.2
KCNT1
NM_001272003.2
c.1885A>Gp.Met629Val
missense
Exon 18 of 31NP_001258932.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNT1
ENST00000371757.7
TSL:1 MANE Select
c.2020A>Gp.Met674Val
missense
Exon 19 of 31ENSP00000360822.2
KCNT1
ENST00000460750.5
TSL:1
n.*1630A>G
non_coding_transcript_exon
Exon 19 of 32ENSP00000418777.1
KCNT1
ENST00000460750.5
TSL:1
n.*1630A>G
3_prime_UTR
Exon 19 of 32ENSP00000418777.1

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152132
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.00
AC:
0
AN:
41764
AF XY:
0.00
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000878
AC:
110
AN:
1252836
Hom.:
0
Cov.:
31
AF XY:
0.0000876
AC XY:
53
AN XY:
604892
show subpopulations
African (AFR)
AF:
0.0000389
AC:
1
AN:
25734
American (AMR)
AF:
0.00
AC:
0
AN:
14594
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
17846
East Asian (EAS)
AF:
0.00
AC:
0
AN:
29886
South Asian (SAS)
AF:
0.00
AC:
0
AN:
56680
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
43526
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5074
European-Non Finnish (NFE)
AF:
0.000106
AC:
107
AN:
1008210
Other (OTH)
AF:
0.0000390
AC:
2
AN:
51286
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
6
12
19
25
31
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:
0.0000197
AC:
3
AN:
152132
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74314
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41438
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
67994
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.508
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.00
Hom.:
0
Bravo
AF:
0.0000302
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.00
AC:
0
ExAC
AF:
0.0000236
AC:
2

ClinVar

ClinVar submissions as Germline

Significance:Uncertain significance
Revision:criteria provided, multiple submitters, no conflicts
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
1
-
Developmental and epileptic encephalopathy, 14;C3554306:Autosomal dominant nocturnal frontal lobe epilepsy 5 (1)
-
1
-
Inborn genetic diseases (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.11
BayesDel_addAF
Benign
-0.12
T
BayesDel_noAF
Benign
-0.42
CADD
Benign
21
DANN
Benign
0.84
DEOGEN2
Benign
0.024
T
Eigen
Benign
-0.094
Eigen_PC
Benign
0.038
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Benign
0.80
T
M_CAP
Benign
0.034
D
MetaRNN
Benign
0.29
T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
1.8
L
PhyloP100
9.0
PrimateAI
Uncertain
0.69
T
PROVEAN
Benign
0.080
N
REVEL
Benign
0.18
Sift
Benign
0.34
T
Sift4G
Benign
0.47
T
Polyphen
0.0010
B
Vest4
0.53
MutPred
0.37
Loss of sheet (P = 0.0457)
MVP
0.47
MPC
0.64
ClinPred
0.80
D
GERP RS
4.0
Varity_R
0.12
gMVP
0.34
Mutation Taster
=71/29
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: rs753401695; hg19: chr9-138664572; API