chr9-135772750-C-T

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BS2

The NM_020822.3(KCNT1):​c.2044C>T​(p.Arg682Trp) variant causes a missense change. The variant allele was found at a frequency of 0.0000132 in 1,441,830 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R682Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000012 ( 1 hom. )

Consequence

KCNT1
NM_020822.3 missense

Scores

10
8

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 3.93

Publications

0 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: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
  • malignant migrating partial seizures of infancy
    Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, G2P
  • 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 -4 ACMG points.

BS2
High AC in GnomAdExome4 at 16 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

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNT1
NM_020822.3
MANE Select
c.2044C>Tp.Arg682Trp
missense
Exon 19 of 31NP_065873.2Q5JUK3-3
KCNT1
NM_001272003.2
c.1909C>Tp.Arg637Trp
missense
Exon 18 of 31NP_001258932.1Q5JUK3-4

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNT1
ENST00000371757.7
TSL:1 MANE Select
c.2044C>Tp.Arg682Trp
missense
Exon 19 of 31ENSP00000360822.2Q5JUK3-3
KCNT1
ENST00000460750.5
TSL:1
n.*1654C>T
non_coding_transcript_exon
Exon 19 of 32ENSP00000418777.1F8WC49
KCNT1
ENST00000460750.5
TSL:1
n.*1654C>T
3_prime_UTR
Exon 19 of 32ENSP00000418777.1F8WC49

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152194
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000483
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000788
AC:
5
AN:
63436
AF XY:
0.000123
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000103
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000138
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000124
AC:
16
AN:
1289636
Hom.:
1
Cov.:
31
AF XY:
0.0000240
AC XY:
15
AN XY:
624928
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
27546
American (AMR)
AF:
0.0000512
AC:
1
AN:
19530
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
19134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
32182
South Asian (SAS)
AF:
0.000160
AC:
10
AN:
62386
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
44444
Middle Eastern (MID)
AF:
0.000192
AC:
1
AN:
5214
European-Non Finnish (NFE)
AF:
0.00000390
AC:
4
AN:
1026032
Other (OTH)
AF:
0.00
AC:
0
AN:
53168
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
1
2
4
5
6
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:
152194
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74350
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41450
American (AMR)
AF:
0.00
AC:
0
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
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:
0.0000147
AC:
1
AN:
68024
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.408
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:
0.0000875
Hom.:
0
Bravo
AF:
0.0000189
ExAC
AF:
0.0000546
AC:
5

ClinVar

ClinVar submissions
Significance:Uncertain significance
Revision:criteria provided, multiple submitters, no conflicts
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
2
-
Developmental and epileptic encephalopathy, 14;C3554306:Autosomal dominant nocturnal frontal lobe epilepsy 5 (2)
-
1
-
Autosomal dominant nocturnal frontal lobe epilepsy 5 (1)
-
1
-
Developmental and epileptic encephalopathy, 14 (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.089
BayesDel_addAF
Benign
-0.26
T
BayesDel_noAF
Benign
-0.35
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Benign
0.24
T
Eigen
Benign
0.17
Eigen_PC
Benign
0.047
FATHMM_MKL
Uncertain
0.86
D
LIST_S2
Uncertain
0.91
D
M_CAP
Uncertain
0.12
D
MetaRNN
Uncertain
0.63
D
MetaSVM
Benign
-0.91
T
MutationAssessor
Uncertain
2.2
M
PhyloP100
3.9
PrimateAI
Uncertain
0.55
T
PROVEAN
Uncertain
-2.7
D
REVEL
Benign
0.16
Sift
Uncertain
0.0010
D
Sift4G
Uncertain
0.0060
D
Polyphen
0.98
D
Vest4
0.60
MutPred
0.30
Loss of disorder (P = 0.0199)
MVP
0.57
MPC
1.1
ClinPred
0.27
T
GERP RS
3.1
Varity_R
0.12
gMVP
0.50
Mutation Taster
=85/15
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs750994724; hg19: chr9-138664596; API