9-135771033-C-T

Variant names:

Variant summary

Our verdict is Benign. The variant received -8 ACMG points: 0P and 8B. BP4_ModerateBP6_ModerateBS2

The NM_020822.3(KCNT1):c.1946C>T(p.Ser649Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000285 in 1,613,016 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict 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. S649T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000028 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 missense

Scores

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: 0.303

Publications

2 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: Benign. The variant received -8 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.11923292).

BP6

Variant 9-135771033-C-T is Benign according to our data. Variant chr9-135771033-C-T is described in ClinVar as Likely_benign. ClinVar VariationId is 473365.Status of the report is criteria_provided_single_submitter, 1 stars.

BS2

High AC in GnomAd4 at 5 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_020822.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNT1	NM_020822.3	MANE Select	c.1946C>T	p.Ser649Leu	missense	Exon 18 of 31	NP_065873.2
	KCNT1	NM_001272003.2		c.1811C>T	p.Ser604Leu	missense	Exon 17 of 31	NP_001258932.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
KCNT1	ENST00000371757.7	TSL:1 MANE Select	c.1946C>T	p.Ser649Leu	missense	Exon 18 of 31	ENSP00000360822.2
KCNT1	ENST00000460750.5	TSL:1	n.*1556C>T		non_coding_transcript_exon	Exon 18 of 32	ENSP00000418777.1
KCNT1	ENST00000460750.5	TSL:1	n.*1556C>T		3_prime_UTR	Exon 18 of 32	ENSP00000418777.1

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152186

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000121

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000122

AC:

AN:

246606

AF XY:

0.0000224

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000292

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000180

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000281

AC:

AN:

1460830

Hom.:

Cov.:

AF XY:

0.0000248

AC XY:

AN XY:

726654

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33466

American (AMR)

AF:

0.0000224

AC:

AN:

44606

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26102

East Asian (EAS)

AF:

0.00

AC:

AN:

39660

South Asian (SAS)

AF:

0.00

AC:

AN:

86048

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53228

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.0000342

AC:

AN:

1111602

Other (OTH)

AF:

0.0000166

AC:

AN:

60352

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.459

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

AF:

0.0000329

AC:

AN:

152186

Hom.:

Cov.:

AF XY:

0.0000673

AC XY:

AN XY:

74348

show subpopulations

African (AFR)

AF:

0.000121

AC:

AN:

41456

American (AMR)

AF:

0.00

AC:

AN:

15284

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5170

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68028

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.575

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome 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

Alfa

AF:

0.0000579

Hom.:

Bravo

AF:

0.0000529

ExAC

AF:

0.00000824

AC:

ClinVar

ClinVar submissions as Germline

Significance:Likely benign

Revision:criteria provided, single submitter

View on ClinVar

Pathogenic

VUS

Benign

Condition

Developmental and epileptic encephalopathy, 14;C3554306:Autosomal dominant nocturnal frontal lobe epilepsy 5 (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.072

BayesDel_addAF

Benign

-0.31

BayesDel_noAF

Benign

-0.60

CADD

Benign

(source)

DANN

Uncertain

0.99

DEOGEN2

Benign

0.065

Eigen

Benign

-1.0

Eigen_PC

Benign

-1.0

FATHMM_MKL

Benign

0.030

LIST_S2

Uncertain

0.89

M_CAP

Uncertain

0.11

MetaRNN

Benign

0.12

MetaSVM

Benign

-0.97

MutationAssessor

Benign

1.8

PhyloP100

0.30

PrimateAI

Benign

0.41

PROVEAN

Benign

-1.5

REVEL

Benign

0.019

Sift

Benign

0.039

Sift4G

Benign

0.21

Polyphen

0.0010

Vest4

0.16

MVP

0.34

MPC

0.56

ClinPred

0.14

GERP RS

1.6

Varity_R

0.062

gMVP

0.43

Mutation Taster

=87/13

polymorphism

(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

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

ClinVar submissions as Germline

Computational scores

Splicing

Publications

Other links and lift over