rs750994724

Positions:

chr9-135772750-C-T

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BS2

The NM_020822.3(KCNT1):c.2044C>T(p.Arg682Trp) variant causes a missense change. The variant allele was found at a frequency of 0.0000132 in 1,441,830 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

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

Exomes 𝑓: 0.000012 ( 1 hom. )

Consequence

KCNT1
NM_020822.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 3.93

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 Likely_benign. Variant got -4 ACMG points.

BS2

High AC in GnomAdExome4 at 16 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNT1	NM_020822.3 linkuse as main transcript	c.2044C>T	p.Arg682Trp	missense_variant	19/31	ENST00000371757.7	NP_065873.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNT1	ENST00000371757.7 linkuse as main transcript	c.2044C>T	p.Arg682Trp	missense_variant	19/31	1	NM_020822.3	ENSP00000360822	A2	Q5JUK3-3

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152194

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000788

AC:

AN:

63436

Hom.:

AF XY:

0.000123

AC XY:

AN XY:

32510

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000103

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000151

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000138

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000124

AC:

AN:

1289636

Hom.:

Cov.:

AF XY:

0.0000240

AC XY:

AN XY:

624928

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000512

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000160

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000390

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152194

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74350

show subpopulations

Gnomad4 AFR

AF:

0.0000483

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000875

Hom.:

Bravo

AF:

0.0000189

ExAC

AF:

0.0000546

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

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

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 09, 2023	This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 682 of the KCNT1 protein (p.Arg682Trp). This variant is present in population databases (rs750994724, gnomAD 0.02%), and has an allele count higher than expected for a pathogenic variant. This variant has not been reported in the literature in individuals affected with KCNT1-related conditions. ClinVar contains an entry for this variant (Variation ID: 571802). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt KCNT1 protein function with a negative predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Oct 31, 2018	- -

Developmental and epileptic encephalopathy, 14

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genomic Research Center, Shahid Beheshti University of Medical Sciences

May 03, 2020

- -

Autosomal dominant nocturnal frontal lobe epilepsy 5

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Aug 10, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.089

BayesDel_addAF

Benign

-0.26

BayesDel_noAF

Benign

-0.35

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Benign

0.24

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

Eigen

Benign

0.17

Eigen_PC

Benign

0.047

FATHMM_MKL

Uncertain

0.86

LIST_S2

Uncertain

0.91

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

M_CAP

Uncertain

0.12

MetaRNN

Uncertain

0.63

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

MetaSVM

Benign

-0.91

MutationAssessor

Uncertain

2.2

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

MutationTaster

Benign

1.0

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

PrimateAI

Uncertain

0.55

PROVEAN

Uncertain

-2.7

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

REVEL

Benign

0.16

Sift

Uncertain

0.0010

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

Sift4G

Uncertain

0.0060

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

Polyphen

0.98

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

Vest4

0.60

MutPred

0.30

.;.;.;.;.;.;Loss of disorder (P = 0.0199);Loss of disorder (P = 0.0199);Loss of disorder (P = 0.0199);.;

MVP

0.57

MPC

1.1

ClinPred

0.27

GERP RS

3.1

Varity_R

0.12

gMVP

0.50

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

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