chr9-135765134-C-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 1P and 4B. PP3BS2

The NM_020822.3(KCNT1):c.1139C>T(p.Ser380Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000684 in 1,461,262 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: 33)

Exomes 𝑓: 0.0000068 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.44

Publications

0 publications found

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 Gene-Disease associations (from GenCC):

childhood-onset epilepsy syndrome
Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
developmental and epileptic encephalopathy, 14
Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
malignant migrating partial seizures of infancy
Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Orphanet
autosomal dominant nocturnal frontal lobe epilepsy 5
Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
autosomal dominant nocturnal frontal lobe epilepsy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

KCNT1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.763

BS2

High AC in GnomAdExome4 at 10 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNT1	NM_020822.3 link	c.1139C>T	p.Ser380Phe	missense_variant	Exon 12 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.1139C>T	p.Ser380Phe	missense_variant	Exon 12 of 31	1	NM_020822.3	ENSP00000360822.2		Q5JUK3-3

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251034

AF XY:

0.00000736

show subpopulations

Gnomad AFR exome

AF:

0.0000617

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000684

AC:

AN:

1461262

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

726922

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44716

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26130

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.00

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52916

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.00000809

AC:

AN:

1111922

Other (OTH)

AF:

0.00

AC:

AN:

60380

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.495

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Cov.:

Alfa

AF:

0.0000282

Hom.:

Bravo

AF:

0.00000378

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

Oct 29, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. The frequency data for this variant (rs765193021) in the population databases is unreliable, as metrics indicate poor quality at this position in the ExAC database. This variant has not been reported in the literature in individuals with a KCNT1-related disease. This sequence change replaces serine with phenylalanine at codon 380 of the KCNT1 protein (p.Ser380Phe). The serine residue is moderately conserved and there is a large physicochemical difference between serine and phenylalanine. 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: "Possibly Damaging"; Align-GVGD: "Class C0"). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.26

BayesDel_addAF

Uncertain

0.073

BayesDel_noAF

Benign

-0.13

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.28

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

Eigen

Uncertain

0.26

Eigen_PC

Uncertain

0.35

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.99

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

M_CAP

Benign

0.022

MetaRNN

Pathogenic

0.76

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

MetaSVM

Benign

-1.1

MutationAssessor

Benign

1.4

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

PhyloP100

7.4

PrimateAI

Pathogenic

0.80

PROVEAN

Uncertain

-3.8

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

REVEL

Uncertain

0.33

Sift

Uncertain

0.0070

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

Sift4G

Uncertain

0.0080

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

Polyphen

0.0020

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

Vest4

0.91

MutPred

0.57

.;.;.;.;.;.;Loss of relative solvent accessibility (P = 0.0306);Loss of relative solvent accessibility (P = 0.0306);Loss of relative solvent accessibility (P = 0.0306);Loss of relative solvent accessibility (P = 0.0306);

MVP

0.58

MPC

1.4

ClinPred

0.99

GERP RS

4.3

Varity_R

0.52

gMVP

0.96

Mutation Taster

=50/50

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over