rs745965148

Positions:

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 3P and 4B. PM2PP3BS2

The NM_020822.3(KCNT1):c.1250G>A(p.Arg417His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000343 in 1,458,026 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 7.83

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:

KCNT1 (HGNC:):

KCNT1 links:

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.831

BS2

High AC in GnomAdExome4 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.1250G>A	p.Arg417His	missense_variant	13/31	ENST00000371757.7	NP_065873.2	Q5JUK3-3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNT1	ENST00000371757.7 linkuse as main transcript	c.1250G>A	p.Arg417His	missense_variant	13/31	1	NM_020822.3	ENSP00000360822.2		Q5JUK3-3

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000818

AC:

AN:

244434

Hom.:

AF XY:

0.0000151

AC XY:

AN XY:

132464

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 SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000182

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000343

AC:

AN:

1458026

Hom.:

Cov.:

AF XY:

0.00000414

AC XY:

AN XY:

724930

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000234

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000270

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ExAC

AF:

0.0000248

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:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 07, 2020

In summary, this variant is a rare missense change with uncertain impact on protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). This variant is present in population databases (rs745965148, ExAC <0.01%) but has not been reported in the literature in individuals with a KCNT1-related disease. This sequence change replaces arginine with histidine at codon 417 of the KCNT1 protein (p.Arg417His). The arginine residue is highly conserved and there is a small physicochemical difference between arginine and histidine. -

Developmental and epileptic encephalopathy, 14

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Mar 15, 2022

- -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Greenwood Genetic Center Diagnostic Laboratories, Greenwood Genetic Center

Oct 22, 2020

- -

Autosomal dominant nocturnal frontal lobe epilepsy 5

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Mar 15, 2022

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.21

BayesDel_addAF

Uncertain

0.12

BayesDel_noAF

Uncertain

-0.070

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.32

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

Eigen

Uncertain

0.35

Eigen_PC

Uncertain

0.36

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

0.99

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

M_CAP

Uncertain

0.15

MetaRNN

Pathogenic

0.83

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

MetaSVM

Benign

-0.40

MutationAssessor

Benign

1.8

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

PrimateAI

Pathogenic

0.79

PROVEAN

Pathogenic

-4.5

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

REVEL

Uncertain

0.54

Sift

Uncertain

0.0020

.;.;D;D;.;.;.;.;T;T

Sift4G

Uncertain

0.010

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

Polyphen

0.90

.;.;.;.;.;.;.;.;P;.

Vest4

0.86

MutPred

0.47

.;.;.;.;.;.;Loss of MoRF binding (P = 0.0447);Loss of MoRF binding (P = 0.0447);Loss of MoRF binding (P = 0.0447);Loss of MoRF binding (P = 0.0447);

MVP

0.79

MPC

1.1

ClinPred

0.98

GERP RS

3.6

Varity_R

0.56

gMVP

0.93

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