rs368876173

Variant summary

Our verdict is Benign. The variant received -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_020822.3(KCNT1):​c.1614C>T​(p.Arg538Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000942 in 1,549,910 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.000079 ( 0 hom., cov: 34)
Exomes 𝑓: 0.000096 ( 2 hom. )

Consequence

KCNT1
NM_020822.3 synonymous

Scores

2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:5

Conservation

PhyloP100: -2.05

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: 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 -21 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.75).
BP6
Variant 9-135770050-C-T is Benign according to our data. Variant chr9-135770050-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 383992.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BP7
Synonymous conserved (PhyloP=-2.05 with no splicing effect.
BS1
Variant frequency is greater than expected in population sas. GnomAd4 allele frequency = 0.0000788 (12/152340) while in subpopulation SAS AF = 0.00124 (6/4834). AF 95% confidence interval is 0.00054. There are 0 homozygotes in GnomAd4. There are 6 alleles in the male GnomAd4 subpopulation. Median coverage is 34. This position passed quality control check.
BS2
High AC in GnomAd4 at 12 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNT1NM_020822.3 linkc.1614C>T p.Arg538Arg synonymous_variant Exon 16 of 31 ENST00000371757.7 NP_065873.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNT1ENST00000371757.7 linkc.1614C>T p.Arg538Arg synonymous_variant Exon 16 of 31 1 NM_020822.3 ENSP00000360822.2

Frequencies

GnomAD3 genomes
AF:
0.0000854
AC:
13
AN:
152222
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000965
Gnomad SAS
AF:
0.00124
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.000378
AC:
58
AN:
153406
AF XY:
0.000345
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000402
Gnomad ASJ exome
AF:
0.000120
Gnomad EAS exome
AF:
0.00290
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000173
Gnomad OTH exome
AF:
0.000920
GnomAD4 exome
AF:
0.0000959
AC:
134
AN:
1397570
Hom.:
2
Cov.:
32
AF XY:
0.000104
AC XY:
72
AN XY:
689524
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
31586
American (AMR)
AF:
0.0000278
AC:
1
AN:
35938
Ashkenazi Jewish (ASJ)
AF:
0.0000398
AC:
1
AN:
25144
East Asian (EAS)
AF:
0.000949
AC:
34
AN:
35816
South Asian (SAS)
AF:
0.000909
AC:
72
AN:
79212
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
48200
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4716
European-Non Finnish (NFE)
AF:
0.00000463
AC:
5
AN:
1079058
Other (OTH)
AF:
0.000363
AC:
21
AN:
57900
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.504
Heterozygous variant carriers
0
7
15
22
30
37
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
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:
0.0000788
AC:
12
AN:
152340
Hom.:
0
Cov.:
34
AF XY:
0.0000806
AC XY:
6
AN XY:
74480
show subpopulations
African (AFR)
AF:
0.0000240
AC:
1
AN:
41582
American (AMR)
AF:
0.00
AC:
0
AN:
15314
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000773
AC:
4
AN:
5172
South Asian (SAS)
AF:
0.00124
AC:
6
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68020
Other (OTH)
AF:
0.000473
AC:
1
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.533
Heterozygous variant carriers
0
2
3
5
6
8
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:
0.0000831
Asia WGS
AF:
0.00144
AC:
5
AN:
3478

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy, 14;C3554306:Autosomal dominant nocturnal frontal lobe epilepsy 5 Benign:1
Oct 21, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

KCNT1-related disorder Benign:1
Apr 01, 2019
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

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

- -

not provided Benign:1
Nov 03, 2020
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

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

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.75
CADD
Benign
5.0
DANN
Benign
0.92
PhyloP100
-2.1
Mutation Taster
=100/0
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: rs368876173; hg19: chr9-138661896; API