9-135772926-C-T

Variant summary

Our verdict is Benign. The variant received -11 ACMG points: 0P and 11B. BP4_StrongBP6_ModerateBP7BS2

The NM_020822.3(KCNT1):​c.2220C>T​(p.Asp740Asp) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000211 in 1,518,880 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 Likely benign (★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000020 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 synonymous

Scores

2

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: -4.50

Publications

6 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 -11 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.57).
BP6
Variant 9-135772926-C-T is Benign according to our data. Variant chr9-135772926-C-T is described in ClinVar as Likely_benign. ClinVar VariationId is 700074.Status of the report is criteria_provided_single_submitter, 1 stars.
BP7
Synonymous conserved (PhyloP=-4.49 with no splicing effect.
BS2
High AC in GnomAdExome4 at 28 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNT1NM_020822.3 linkc.2220C>T p.Asp740Asp synonymous_variant Exon 19 of 31 ENST00000371757.7 NP_065873.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNT1ENST00000371757.7 linkc.2220C>T p.Asp740Asp synonymous_variant Exon 19 of 31 1 NM_020822.3 ENSP00000360822.2

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152182
Hom.:
0
Cov.:
33
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:
0.000193
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:
0.0000159
AC:
2
AN:
126108
AF XY:
0.0000295
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000969
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000194
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000205
AC:
28
AN:
1366580
Hom.:
0
Cov.:
31
AF XY:
0.0000164
AC XY:
11
AN XY:
672564
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
30840
American (AMR)
AF:
0.00
AC:
0
AN:
30714
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
22932
East Asian (EAS)
AF:
0.0000281
AC:
1
AN:
35610
South Asian (SAS)
AF:
0.0000135
AC:
1
AN:
73922
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
43098
Middle Eastern (MID)
AF:
0.000184
AC:
1
AN:
5446
European-Non Finnish (NFE)
AF:
0.0000234
AC:
25
AN:
1067472
Other (OTH)
AF:
0.00
AC:
0
AN:
56546
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.459
Heterozygous variant carriers
0
2
4
5
7
9
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:
0.0000263
AC:
4
AN:
152300
Hom.:
0
Cov.:
33
AF XY:
0.0000403
AC XY:
3
AN XY:
74452
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41572
American (AMR)
AF:
0.00
AC:
0
AN:
15304
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.000194
AC:
1
AN:
5166
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10630
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68020
Other (OTH)
AF:
0.00
AC:
0
AN:
2110
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.513
Heterozygous variant carriers
0
1
2
2
3
4
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:
0.00
Hom.:
0
Bravo
AF:
0.0000189

ClinVar

Significance: Likely benign
Submissions summary: Benign:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy, 14;C3554306:Autosomal dominant nocturnal frontal lobe epilepsy 5 Benign:1
Feb 24, 2024
Labcorp Genetics (formerly Invitae), Labcorp
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
-0.57
CADD
Benign
0.50
DANN
Benign
0.80
PhyloP100
-4.5

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.070
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: rs148162797; hg19: chr9-138664772; API