chr9-135786447-G-A

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4BP6BS2

The NM_020822.3(KCNT1):​c.3428G>A​(p.Arg1143His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000159 in 1,446,354 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1143C) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 missense

Scores

2
9
8

Clinical Significance

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

Conservation

PhyloP100: 7.84

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: Likely_benign. The variant received -6 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.40028757).
BP6
Variant 9-135786447-G-A is Benign according to our data. Variant chr9-135786447-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 540582.
BS2
High AC in GnomAdExome4 at 23 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNT1NM_020822.3 linkc.3428G>A p.Arg1143His missense_variant Exon 29 of 31 ENST00000371757.7 NP_065873.2 Q5JUK3-3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNT1ENST00000371757.7 linkc.3428G>A p.Arg1143His missense_variant Exon 29 of 31 1 NM_020822.3 ENSP00000360822.2 Q5JUK3-3

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00000472
AC:
1
AN:
211884
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000110
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000159
AC:
23
AN:
1446354
Hom.:
0
Cov.:
36
AF XY:
0.0000181
AC XY:
13
AN XY:
718730
show subpopulations
African (AFR)
AF:
0.0000304
AC:
1
AN:
32942
American (AMR)
AF:
0.00
AC:
0
AN:
42910
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25782
East Asian (EAS)
AF:
0.0000256
AC:
1
AN:
39082
South Asian (SAS)
AF:
0.00
AC:
0
AN:
84560
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
50558
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5076
European-Non Finnish (NFE)
AF:
0.0000181
AC:
20
AN:
1105830
Other (OTH)
AF:
0.0000168
AC:
1
AN:
59614
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.468
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
Cov.:
33
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not specified Uncertain:1
May 03, 2020
Genomic Research Center, Shahid Beheshti University of Medical Sciences
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Developmental and epileptic encephalopathy, 14;C3554306:Autosomal dominant nocturnal frontal lobe epilepsy 5 Benign:1
Nov 15, 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
AlphaMissense
Benign
0.24
BayesDel_addAF
Benign
0.0026
T
BayesDel_noAF
Benign
-0.23
CADD
Uncertain
26
DANN
Uncertain
1.0
DEOGEN2
Benign
0.18
.;.;.;.;.;.;.;.;T;.
Eigen
Uncertain
0.46
Eigen_PC
Uncertain
0.35
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Pathogenic
0.99
D;D;D;D;D;D;D;D;D;D
M_CAP
Uncertain
0.10
D
MetaRNN
Benign
0.40
T;T;T;T;T;T;T;T;T;T
MetaSVM
Benign
-0.75
T
MutationAssessor
Uncertain
2.3
.;.;.;.;.;.;.;.;M;.
PhyloP100
7.8
PrimateAI
Uncertain
0.57
T
PROVEAN
Benign
-2.0
.;.;N;.;.;.;.;.;.;N
REVEL
Uncertain
0.36
Sift
Uncertain
0.013
.;.;D;.;.;.;.;.;.;D
Sift4G
Uncertain
0.020
D;D;T;D;D;D;T;D;D;D
Vest4
0.51
MVP
0.71
MPC
0.12
ClinPred
0.95
D
GERP RS
4.8
Varity_R
0.17
gMVP
0.36
Mutation Taster
=60/40
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: rs1182743416; hg19: chr9-138678293; API