rs368339692

Variant summary

Our verdict is Benign. Variant got -19 ACMG points: 1P and 20B. PP3BP4_StrongBP6_Very_StrongBS1BS2

The NM_020822.3(KCNT1):c.3437G>A(p.Arg1146His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000244 in 1,600,734 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1146C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00016 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00025 ( 1 hom. )

Consequence

KCNT1
NM_020822.3 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:6

Conservation

PhyloP100: 9.68

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 -19 ACMG points.

PP3

Multiple lines of computational evidence support a deleterious effect 6: AlphaMissense, Cadd, Dann, Eigen, FATHMM_MKL, phyloP100way_vertebrate [when BayesDel_addAF, MetaRNN, MutationTaster was below the threshold]

BP4

Computational evidence support a benign effect (MetaRNN=0.052166134).

BP6

Variant 9-135786456-G-A is Benign according to our data. Variant chr9-135786456-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 473390.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BS1

Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.000164 (25/152352) while in subpopulation SAS AF= 0.00373 (18/4832). AF 95% confidence interval is 0.00241. There are 0 homozygotes in gnomad4. There are 16 alleles in male gnomad4 subpopulation. This position pass quality control queck.

BS2

High AC in GnomAd at 25 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNT1	NM_020822.3 linkuse as main transcript	c.3437G>A	p.Arg1146His	missense_variant	29/31	ENST00000371757.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNT1	ENST00000371757.7 linkuse as main transcript	c.3437G>A	p.Arg1146His	missense_variant	29/31	1	NM_020822.3	A2	Q5JUK3-3

Frequencies

GnomAD3 genomes

AF:

0.000164

AC:

AN:

152234

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000482

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00372

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000375

AC:

AN:

216266

Hom.:

AF XY:

0.000574

AC XY:

AN XY:

120122

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000623

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000608

Gnomad SAS exome

AF:

0.00261

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000322

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000253

AC:

366

AN:

1448382

Hom.:

Cov.:

AF XY:

0.000347

AC XY:

250

AN XY:

719946

show subpopulations

Gnomad4 AFR exome

AF:

0.0000608

Gnomad4 AMR exome

AF:

0.0000697

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000765

Gnomad4 SAS exome

AF:

0.00334

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000578

Gnomad4 OTH exome

AF:

0.000168

GnomAD4 genome

AF:

0.000164

AC:

AN:

152352

Hom.:

Cov.:

AF XY:

0.000215

AC XY:

AN XY:

74500

show subpopulations

Gnomad4 AFR

AF:

0.0000481

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00373

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000139

Hom.:

Bravo

AF:

0.0000756

ESP6500AA

AF:

0.000235

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000354

AC:

Asia WGS

AF:

0.00115

AC:

AN:

3478

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

KCNT1-related condition

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Mar 21, 2022

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;C3554306:Autosomal dominant nocturnal frontal lobe epilepsy 5

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Jan 24, 2024

- -

Inborn genetic diseases

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 11, 2018

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. -

not provided

Benign:1

Benign, criteria provided, single submitter

clinical testing

GeneDx

May 27, 2020

- -

Developmental and epileptic encephalopathy, 14

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Mar 15, 2022

- -

Autosomal dominant nocturnal frontal lobe epilepsy 5

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Mar 15, 2022

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.59

BayesDel_addAF

Benign

-0.17

BayesDel_noAF

Uncertain

-0.030

Cadd

Pathogenic

Dann

Pathogenic

1.0

Eigen

Pathogenic

0.72

Eigen_PC

Uncertain

0.61

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

1.0

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

M_CAP

Uncertain

0.27

MetaRNN

Benign

0.052

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

MetaSVM

Benign

-0.34

MutationTaster

Benign

1.0

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

PrimateAI

Uncertain

0.77

REVEL

Uncertain

0.47

Sift4G

Uncertain

0.0020

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

Vest4

0.88

MVP

0.71

MPC

0.52

ClinPred

0.18

GERP RS

4.8

Varity_R

0.77

gMVP

0.56

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