rs796214553

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 8P and 5B. PVS1BP6BS2

The NM_020822.3(KCNT1):​c.1077_1078delAG​(p.Gly361GlnfsTer134) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000036 in 1,613,062 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. S359S) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000072 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000032 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 frameshift

Scores

Not classified

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:1

Conservation

PhyloP100: 7.56

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: Uncertain_significance. The variant received 3 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
BP6
Variant 9-135765071-CAG-C is Benign according to our data. Variant chr9-135765071-CAG-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 289274.
BS2
High AC in GnomAd4 at 11 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.1077_1078delAGp.Gly361GlnfsTer134
frameshift
Exon 12 of 31NP_065873.2
KCNT1
NM_001272003.2
c.942_943delAGp.Gly316GlnfsTer134
frameshift
Exon 11 of 31NP_001258932.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNT1
ENST00000371757.7
TSL:1 MANE Select
c.1077_1078delAGp.Gly361GlnfsTer134
frameshift
Exon 12 of 31ENSP00000360822.2
KCNT1
ENST00000460750.5
TSL:1
n.*687_*688delAG
non_coding_transcript_exon
Exon 12 of 32ENSP00000418777.1
KCNT1
ENST00000460750.5
TSL:1
n.*687_*688delAG
3_prime_UTR
Exon 12 of 32ENSP00000418777.1

Frequencies

GnomAD3 genomes
AF:
0.0000723
AC:
11
AN:
152182
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000483
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00202
Gnomad EAS
AF:
0.00
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:
0.0000719
AC:
18
AN:
250296
AF XY:
0.0000664
show subpopulations
Gnomad AFR exome
AF:
0.0000620
Gnomad AMR exome
AF:
0.0000290
Gnomad ASJ exome
AF:
0.00100
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000266
Gnomad OTH exome
AF:
0.000328
GnomAD4 exome
AF:
0.0000322
AC:
47
AN:
1460880
Hom.:
0
AF XY:
0.0000344
AC XY:
25
AN XY:
726728
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
AN:
44710
Ashkenazi Jewish (ASJ)
AF:
0.000689
AC:
18
AN:
26124
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39692
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52672
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.0000234
AC:
26
AN:
1111816
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60370
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.479
Heterozygous variant carriers
0
3
6
10
13
16
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:
0.0000723
AC:
11
AN:
152182
Hom.:
0
Cov.:
32
AF XY:
0.0000807
AC XY:
6
AN XY:
74346
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41436
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00202
AC:
7
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
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:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.489
Heterozygous variant carriers
0
1
3
4
6
7
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:
0.000182
Hom.:
0
Bravo
AF:
0.0000453

ClinVar

ClinVar submissions as Germline

Significance:Conflicting classifications of pathogenicity
Revision:criteria provided, conflicting classifications
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
2
-
not provided (2)
-
-
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
PhyloP100
7.6
Mutation Taster
=21/179
disease causing (fs/PTC)

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: rs796214553; hg19: chr9-138656917; API