NM_020822.3:c.3685A>G

Variant summary

Our verdict is Benign. The variant received -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_020822.3(KCNT1):​c.3685A>G​(p.Thr1229Ala) variant causes a missense change. The variant allele was found at a frequency of 0.000801 in 1,605,654 control chromosomes in the GnomAD database, including 3 homozygotes. 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 Likely benign (★★).

Frequency

Genomes: 𝑓 0.00055 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00083 ( 3 hom. )

Consequence

KCNT1
NM_020822.3 missense

Scores

2
16

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:11

Conservation

PhyloP100: 4.60

Publications

4 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: Benign. The variant received -20 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.032767117).
BP6
Variant 9-135792138-A-G is Benign according to our data. Variant chr9-135792138-A-G is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 378038.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS1
Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.000553 (84/151986) while in subpopulation NFE AF = 0.00112 (76/67964). AF 95% confidence interval is 0.000916. There are 0 homozygotes in GnomAd4. There are 40 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
BS2
High AC in GnomAd4 at 84 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.3685A>Gp.Thr1229Ala
missense
Exon 31 of 31NP_065873.2Q5JUK3-3
KCNT1
NM_001272003.2
c.3613A>Gp.Thr1205Ala
missense
Exon 31 of 31NP_001258932.1Q5JUK3-4

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNT1
ENST00000371757.7
TSL:1 MANE Select
c.3685A>Gp.Thr1229Ala
missense
Exon 31 of 31ENSP00000360822.2Q5JUK3-3
KCNT1
ENST00000460750.5
TSL:1
n.*3358A>G
non_coding_transcript_exon
Exon 32 of 32ENSP00000418777.1F8WC49
KCNT1
ENST00000460750.5
TSL:1
n.*3358A>G
3_prime_UTR
Exon 32 of 32ENSP00000418777.1F8WC49

Frequencies

GnomAD3 genomes
AF:
0.000553
AC:
84
AN:
151868
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000726
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000328
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:
0.00112
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000498
AC:
120
AN:
240930
AF XY:
0.000464
show subpopulations
Gnomad AFR exome
AF:
0.000190
Gnomad AMR exome
AF:
0.0000583
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00103
Gnomad OTH exome
AF:
0.000168
GnomAD4 exome
AF:
0.000827
AC:
1202
AN:
1453668
Hom.:
3
Cov.:
32
AF XY:
0.000834
AC XY:
603
AN XY:
723386
show subpopulations
African (AFR)
AF:
0.0000896
AC:
3
AN:
33468
American (AMR)
AF:
0.0000448
AC:
2
AN:
44620
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26076
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39660
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86018
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
46162
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00106
AC:
1173
AN:
1111600
Other (OTH)
AF:
0.000398
AC:
24
AN:
60298
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.470
Heterozygous variant carriers
0
64
127
191
254
318
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
44
88
132
176
220
<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:
0.000553
AC:
84
AN:
151986
Hom.:
0
Cov.:
32
AF XY:
0.000538
AC XY:
40
AN XY:
74298
show subpopulations
African (AFR)
AF:
0.0000724
AC:
3
AN:
41446
American (AMR)
AF:
0.000327
AC:
5
AN:
15270
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3464
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5134
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4790
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00112
AC:
76
AN:
67964
Other (OTH)
AF:
0.00
AC:
0
AN:
2104
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.542
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

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:
0.000817
Hom.:
0
Bravo
AF:
0.000540
TwinsUK
AF:
0.000809
AC:
3
ALSPAC
AF:
0.00156
AC:
6
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000698
AC:
6
ExAC
AF:
0.000511
AC:
62
Asia WGS
AF:
0.000289
AC:
2
AN:
3478
EpiCase
AF:
0.00131
EpiControl
AF:
0.000535

ClinVar

ClinVar submissions
Significance:Benign/Likely benign
Revision:criteria provided, multiple submitters, no conflicts
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
-
5
not provided (5)
-
-
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)
-
-
1
Inborn genetic diseases (1)
-
-
1
KCNT1-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.094
BayesDel_addAF
Benign
-0.43
T
BayesDel_noAF
Benign
-0.39
CADD
Benign
20
DANN
Benign
0.93
DEOGEN2
Benign
0.043
T
Eigen
Benign
-0.21
Eigen_PC
Benign
-0.12
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Benign
0.81
T
M_CAP
Benign
0.040
D
MetaRNN
Benign
0.033
T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
0.81
L
PhyloP100
4.6
PrimateAI
Uncertain
0.51
T
PROVEAN
Benign
-1.1
N
REVEL
Benign
0.14
Sift
Benign
0.075
T
Sift4G
Benign
0.20
T
Vest4
0.60
MVP
0.44
MPC
0.090
ClinPred
0.026
T
GERP RS
4.7
Varity_R
0.093
gMVP
0.54
Mutation Taster
=66/34
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: rs74533482; hg19: chr9-138683984; API