rs375403065

Positions:

chr9-135772927-G-A

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_ModerateBS2

The ENST00000371757.7(KCNT1):c.2221G>A(p.Asp741Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000151 in 1,519,918 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D741A) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000013 ( 0 hom. )

Consequence

KCNT1
ENST00000371757.7 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 9.76

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 -6 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.24756396).

BS2

High AC in GnomAd4 at 5 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNT1	NM_020822.3 linkuse as main transcript	c.2221G>A	p.Asp741Asn	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.2221G>A	p.Asp741Asn	missense_variant	19/31	1	NM_020822.3	ENSP00000360822	A2	Q5JUK3-3

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152180

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000965

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.0000132

AC:

AN:

1367620

Hom.:

Cov.:

AF XY:

0.0000149

AC XY:

AN XY:

673126

show subpopulations

Gnomad4 AFR exome

AF:

0.0000647

Gnomad4 AMR exome

AF:

0.0000324

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000135

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000122

Gnomad4 OTH exome

AF:

0.0000177

GnomAD4 genome

AF:

0.0000328

AC:

AN:

152298

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74446

show subpopulations

Gnomad4 AFR

AF:

0.000120

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:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000667

Hom.:

Bravo

AF:

0.0000604

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.000228

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000256

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy, 14;C3554306:Autosomal dominant nocturnal frontal lobe epilepsy 5

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 22, 2023

This sequence change replaces aspartic acid, which is acidic and polar, with asparagine, which is neutral and polar, at codon 741 of the KCNT1 protein (p.Asp741Asn). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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: 540565). 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. 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.083

BayesDel_addAF

Benign

-0.14

BayesDel_noAF

Benign

-0.44

CADD

Uncertain

DANN

Benign

0.96

DEOGEN2

Benign

0.027

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

Eigen

Benign

-0.20

Eigen_PC

Benign

-0.19

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.89

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

M_CAP

Uncertain

0.087

MetaRNN

Benign

0.25

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

MetaSVM

Benign

-0.42

MutationAssessor

Benign

1.2

.;.;.;.;.;.;.;.;L;.

MutationTaster

Benign

1.0

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

PrimateAI

Uncertain

0.54

PROVEAN

Benign

-0.91

.;.;N;.;.;.;.;.;N;N

REVEL

Benign

0.26

Sift

Benign

0.59

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

Sift4G

Benign

0.33

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

Polyphen

0.081

.;.;.;.;.;.;.;.;B;.

Vest4

0.39

MVP

0.72

MPC

0.62

ClinPred

0.14

GERP RS

3.9

Varity_R

0.094

gMVP

0.42

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.040

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