9-135772757-C-T

Variant names:

Variant summary

Our verdict is Benign. The variant received -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_020822.3(KCNT1):c.2051C>T(p.Thr684Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000897 in 1,471,662 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/22 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. T684P) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00017 ( 1 hom., cov: 33)

Exomes 𝑓: 0.000080 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 missense

Scores

Clinical Significance

Likely benign criteria provided, multiple submitters, no conflicts B:5

Conservation

PhyloP100: 1.64

Publications

1 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 -20 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.0074207187).

BP6

Variant 9-135772757-C-T is Benign according to our data. Variant chr9-135772757-C-T is described in ClinVar as Likely_benign. ClinVar VariationId is 385914.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BS1

Variant frequency is greater than expected in population eas. GnomAd4 allele frequency = 0.000171 (26/152322) while in subpopulation EAS AF = 0.00406 (21/5176). AF 95% confidence interval is 0.00272. There are 1 homozygotes in GnomAd4. There are 18 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.

BS2

High AC in GnomAd4 at 26 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.2051C>T	p.Thr684Met	missense	Exon 19 of 31	NP_065873.2
	KCNT1	NM_001272003.2		c.1916C>T	p.Thr639Met	missense	Exon 18 of 31	NP_001258932.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
KCNT1	ENST00000371757.7	TSL:1 MANE Select	c.2051C>T	p.Thr684Met	missense	Exon 19 of 31	ENSP00000360822.2
KCNT1	ENST00000460750.5	TSL:1	n.*1661C>T		non_coding_transcript_exon	Exon 19 of 32	ENSP00000418777.1
KCNT1	ENST00000460750.5	TSL:1	n.*1661C>T		3_prime_UTR	Exon 19 of 32	ENSP00000418777.1

Frequencies

GnomAD3 genomes

AF:

0.000171

AC:

AN:

152204

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00405

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000455

AC:

AN:

81316

AF XY:

0.000452

show subpopulations

Gnomad AFR exome

AF:

0.000176

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00398

Gnomad FIN exome

AF:

0.000173

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000803

AC:

106

AN:

1319340

Hom.:

Cov.:

AF XY:

0.0000763

AC XY:

AN XY:

642454

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

29018

American (AMR)

AF:

0.00

AC:

AN:

24344

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

20218

East Asian (EAS)

AF:

0.00237

AC:

AN:

33764

South Asian (SAS)

AF:

0.000105

AC:

AN:

66362

European-Finnish (FIN)

AF:

0.0000888

AC:

AN:

45056

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5314

European-Non Finnish (NFE)

AF:

0.00000673

AC:

AN:

1040706

Other (OTH)

AF:

0.000147

AC:

AN:

54558

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.489

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:

0.000171

AC:

AN:

152322

Hom.:

Cov.:

AF XY:

0.000242

AC XY:

AN XY:

74476

show subpopulations

African (AFR)

AF:

0.0000481

AC:

AN:

41570

American (AMR)

AF:

0.000131

AC:

AN:

15308

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00406

AC:

AN:

5176

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68022

Other (OTH)

AF:

0.00

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.517

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:

0.00

Hom.:

Bravo

AF:

0.000110

ExAC

AF:

0.000164

AC:

Asia WGS

AF:

0.000577

AC:

AN:

3478

ClinVar

ClinVar submissions as Germline

Significance:Likely benign

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

Autosomal dominant nocturnal frontal lobe epilepsy 5 (1)

Developmental and epileptic encephalopathy, 14 (1)

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

Inborn genetic diseases (1)

not provided (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.079

BayesDel_addAF

Benign

-0.60

BayesDel_noAF

Benign

-0.64

CADD

Benign

(source)

DANN

Benign

0.97

DEOGEN2

Benign

0.059

Eigen

Benign

-0.40

Eigen_PC

Benign

-0.51

FATHMM_MKL

Benign

0.11

LIST_S2

Benign

0.76

M_CAP

Uncertain

0.19

MetaRNN

Benign

0.0074

MetaSVM

Benign

-1.0

MutationAssessor

Benign

1.6

PhyloP100

1.6

PrimateAI

Benign

0.46

PROVEAN

Benign

-1.3

REVEL

Benign

0.067

Sift

Uncertain

0.016

Sift4G

Uncertain

0.039

Polyphen

0.65

Vest4

0.38

MutPred

0.16

Loss of phosphorylation at T665 (P = 0.0143)

MVP

0.42

MPC

0.80

ClinPred

0.025

GERP RS

4.0

Varity_R

0.028

gMVP

0.35

Mutation Taster

=85/15

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