Variant 9-135757376-A-T details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_020822.3(KCNT1):c.754A>T(p.Met252Leu) variant causes a missense change. The variant allele was found at a frequency of 0.000000687 in 1,456,220 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 31)

Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.77

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:

KCNT1 (HGNC:):

KCNT1 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNT1	NM_020822.3 linkuse as main transcript	c.754A>T	p.Met252Leu	missense_variant	9/31	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.754A>T	p.Met252Leu	missense_variant	9/31	1	NM_020822.3	ENSP00000360822.2		Q5JUK3-3

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.87e-7

AC:

AN:

1456220

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

724720

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:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

8.99e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

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

Jul 11, 2018

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with KCNT1-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces methionine with leucine at codon 252 of the KCNT1 protein (p.Met252Leu). The methionine residue is moderately conserved and there is a small physicochemical difference between methionine and leucine. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.36

BayesDel_addAF

Pathogenic

0.39

BayesDel_noAF

Pathogenic

0.33

CADD

Uncertain

DANN

Benign

0.97

DEOGEN2

Benign

0.28

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

Eigen

Benign

0.0027

Eigen_PC

Benign

0.13

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.96

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

M_CAP

Uncertain

0.13

MetaRNN

Uncertain

0.64

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

MetaSVM

Uncertain

0.61

MutationAssessor

Uncertain

2.2

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

PrimateAI

Pathogenic

0.85

PROVEAN

Uncertain

-2.4

.;.;N;D;N;.;.;.;.;N;N

REVEL

Uncertain

0.29

Sift

Benign

0.056

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

Sift4G

Uncertain

0.031

D;D;D;T;D;D;D;D;D;D;D

Polyphen

0.0

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

Vest4

0.64

MutPred

0.48

.;.;.;.;.;.;.;Loss of stability (P = 0.2237);Loss of stability (P = 0.2237);Loss of stability (P = 0.2237);Loss of stability (P = 0.2237);

MVP

0.81

MPC

0.61

ClinPred

0.95

GERP RS

4.6

Varity_R

0.59

gMVP

0.91

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