NM_020822.3:c.3340C>T

Variant names:

Variant summary

Our verdict is Benign. Variant got -18 ACMG points: 0P and 18B. BP4_ModerateBP6_Very_StrongBS1BS2

The NM_020822.3(KCNT1):c.3340C>T(p.Arg1114Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000504 in 1,582,344 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 0.00037 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00052 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:9

Conservation

PhyloP100: 2.79

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -18 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.18138194).

BP6

Variant 9-135786359-C-T is Benign according to our data. Variant chr9-135786359-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 211243.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr9-135786359-C-T is described in Lovd as [Likely_benign].

BS1

Variant frequency is greater than expected in population amr. gnomad4 allele frequency = 0.000368 (56/152278) while in subpopulation AMR AF= 0.000979 (15/15314). AF 95% confidence interval is 0.000603. There are 0 homozygotes in gnomad4. There are 23 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

BS2

High AC in GnomAd4 at 56 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNT1	NM_020822.3 link	c.3340C>T	p.Arg1114Trp	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
KCNT1	ENST00000371757.7 link	c.3340C>T	p.Arg1114Trp	missense_variant	Exon 29 of 31	1	NM_020822.3	ENSP00000360822.2		Q5JUK3-3

Frequencies

GnomAD3 genomes

AF:

0.000368

AC:

AN:

152162

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000981

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:

0.000544

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.000337

AC:

AN:

181208

Hom.:

AF XY:

0.000380

AC XY:

AN XY:

99880

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000899

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000385

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000446

Gnomad OTH exome

AF:

0.000418

GnomAD4 exome

AF:

0.000518

AC:

741

AN:

1430066

Hom.:

Cov.:

AF XY:

0.000524

AC XY:

371

AN XY:

708426

show subpopulations

Gnomad4 AFR exome

AF:

0.0000913

Gnomad4 AMR exome

AF:

0.000837

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000723

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000594

Gnomad4 OTH exome

AF:

0.000794

GnomAD4 genome

AF:

0.000368

AC:

AN:

152278

Hom.:

Cov.:

AF XY:

0.000309

AC XY:

AN XY:

74456

show subpopulations

Gnomad4 AFR

AF:

0.0000722

Gnomad4 AMR

AF:

0.000979

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000544

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.0000435

Hom.:

Bravo

AF:

0.000589

ESP6500AA

AF:

0.000277

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000231

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3470

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:9

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Benign:3

Apr 03, 2017

Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 15, 2021

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 01, 2025

CeGaT Center for Human Genetics Tuebingen

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

KCNT1: BS1, BS2 -

not specified

Benign:1

Mar 30, 2015

Genetic Services Laboratory, University of Chicago

Significance: Likely benign

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

Jan 11, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Inborn genetic diseases

Benign:1

May 03, 2019

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

KCNT1-related disorder

Benign:1

Sep 17, 2020

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

- -

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

AlphaMissense

Benign

0.29

BayesDel_addAF

Benign

-0.064

BayesDel_noAF

Uncertain

0.060

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.27

.;.;.;.;.;.;.;.;T;.

Eigen

Uncertain

0.41

Eigen_PC

Uncertain

0.29

FATHMM_MKL

Uncertain

0.94

LIST_S2

Pathogenic

1.0

D;D;D;D;D;D;D;D;D;D

M_CAP

Pathogenic

0.46

MetaRNN

Benign

0.18

T;T;T;T;T;T;T;T;T;T

MetaSVM

Benign

-0.69

MutationAssessor

Uncertain

2.3

.;.;.;.;.;.;.;.;M;.

PrimateAI

Uncertain

0.66

PROVEAN

Uncertain

-3.1

.;.;D;.;.;D;.;.;D;D

REVEL

Uncertain

0.34

Sift

Uncertain

0.0030

.;.;D;.;.;D;.;.;D;D

Sift4G

Uncertain

0.045

D;T;D;T;T;D;D;D;D;D

Vest4

0.74

MVP

0.62

MPC

0.39

ClinPred

0.095

GERP RS

3.8

Varity_R

0.17

gMVP

0.48

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over