NM_020822.3:c.1927C>T

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_ModerateBP6BS2

The NM_020822.3(KCNT1):​c.1927C>T​(p.Arg643Trp) variant causes a missense change. The variant allele was found at a frequency of 0.0000254 in 1,613,568 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R643Q) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 34)
Exomes 𝑓: 0.000026 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 missense

Scores

6
13

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:3

Conservation

PhyloP100: 3.75

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: Benign. The variant received -7 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.18533307).
BP6
Variant 9-135771014-C-T is Benign according to our data. Variant chr9-135771014-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 194883.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=3, Likely_benign=3}.
BS2
High AC in GnomAdExome4 at 38 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNT1NM_020822.3 linkc.1927C>T p.Arg643Trp missense_variant Exon 18 of 31 ENST00000371757.7 NP_065873.2 Q5JUK3-3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNT1ENST00000371757.7 linkc.1927C>T p.Arg643Trp missense_variant Exon 18 of 31 1 NM_020822.3 ENSP00000360822.2 Q5JUK3-3

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152190
Hom.:
0
Cov.:
34
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:
0.000193
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000362
AC:
9
AN:
248784
AF XY:
0.0000371
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000273
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000356
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000260
AC:
38
AN:
1461378
Hom.:
0
Cov.:
33
AF XY:
0.0000220
AC XY:
16
AN XY:
726966
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33472
American (AMR)
AF:
0.00
AC:
0
AN:
44670
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26124
East Asian (EAS)
AF:
0.000101
AC:
4
AN:
39688
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86146
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53332
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000288
AC:
32
AN:
1111796
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60382
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.446
Heterozygous variant carriers
0
3
6
8
11
14
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:
0.0000197
AC:
3
AN:
152190
Hom.:
0
Cov.:
34
AF XY:
0.00
AC XY:
0
AN XY:
74340
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41442
American (AMR)
AF:
0.00
AC:
0
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5178
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.542
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000494
Hom.:
0
Bravo
AF:
0.0000189
ExAC
AF:
0.0000577
AC:
7

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:3Benign:3
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:1
Sep 08, 2014
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Aug 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

KCNT1: BP4 -

Developmental and epileptic encephalopathy, 14 Uncertain:1
Mar 15, 2022
Genome-Nilou Lab
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Autosomal dominant nocturnal frontal lobe epilepsy 5 Uncertain:1
Mar 15, 2022
Genome-Nilou Lab
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Developmental and epileptic encephalopathy, 14;C3554306:Autosomal dominant nocturnal frontal lobe epilepsy 5 Benign:1
Nov 05, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Benign:1
Aug 20, 2024
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.094
BayesDel_addAF
Benign
-0.36
T
BayesDel_noAF
Benign
-0.45
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Benign
0.085
.;.;.;.;.;.;.;.;T;.
Eigen
Benign
0.046
Eigen_PC
Benign
0.081
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Uncertain
0.96
D;D;D;D;D;D;D;D;D;D
M_CAP
Uncertain
0.13
D
MetaRNN
Benign
0.19
T;T;T;T;T;T;T;T;T;T
MetaSVM
Benign
-0.94
T
MutationAssessor
Benign
0.90
.;.;.;.;.;.;.;.;L;.
PhyloP100
3.8
PrimateAI
Benign
0.38
T
PROVEAN
Benign
-1.7
.;.;N;N;.;.;.;.;N;N
REVEL
Benign
0.053
Sift
Uncertain
0.0040
.;.;D;D;.;.;.;.;D;D
Sift4G
Uncertain
0.014
D;D;D;D;D;D;D;D;D;D
Polyphen
0.74
.;.;.;.;.;.;.;.;P;.
Vest4
0.31
MVP
0.58
MPC
0.66
ClinPred
0.26
T
GERP RS
3.9
Varity_R
0.23
gMVP
0.45
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: rs532620254; hg19: chr9-138662860; COSMIC: COSV53706081; COSMIC: COSV53706081; API