NM_020822.3:c.1444G>A

Variant names:

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 1P and 4B. PP3BS2

The NM_020822.3(KCNT1):c.1444G>A(p.Ala482Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000868 in 1,613,240 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: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 9.77

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 -3 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.752

BS2

High AC in GnomAdExome4 at 12 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNT1	NM_020822.3 link	c.1444G>A	p.Ala482Thr	missense_variant	Exon 15 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.1444G>A	p.Ala482Thr	missense_variant	Exon 15 of 31	1	NM_020822.3	ENSP00000360822.2		Q5JUK3-3

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152164

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000400

AC:

AN:

249788

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135408

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:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000821

AC:

AN:

1460958

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

726836

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.0000383

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000809

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152282

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74454

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

ExAC

AF:

0.00000824

AC:

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

Jul 25, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. 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 expected to disrupt KCNT1 protein function. ClinVar contains an entry for this variant (Variation ID: 473359). This missense change has been observed in at least one individual who was not affected with KCNT1-related conditions (Invitae). This missense change has been observed in individual(s) with clinical features of KCNT1-related conditions (Invitae). This variant is present in population databases (rs577633745, gnomAD 0.003%). This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 482 of the KCNT1 protein (p.Ala482Thr). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.89

BayesDel_addAF

Pathogenic

0.17

BayesDel_noAF

Uncertain

0.11

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.40

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

Eigen

Uncertain

0.67

Eigen_PC

Uncertain

0.60

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

1.0

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

M_CAP

Uncertain

0.21

MetaRNN

Pathogenic

0.75

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

MetaSVM

Uncertain

0.00020

MutationAssessor

Uncertain

2.6

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

PrimateAI

Pathogenic

0.79

PROVEAN

Uncertain

-3.8

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

REVEL

Pathogenic

0.65

Sift

Uncertain

0.0010

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

Sift4G

Pathogenic

0.0

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

Polyphen

0.98

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

Vest4

0.84

MutPred

0.53

.;.;.;.;.;.;Loss of loop (P = 0.0203);Loss of loop (P = 0.0203);Loss of loop (P = 0.0203);Loss of loop (P = 0.0203);

MVP

0.77

MPC

1.6

ClinPred

1.0

GERP RS

3.8

Varity_R

0.74

gMVP

0.86

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