9-135772929-C-T

Variant names:

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 0P and 10B. BP4_StrongBP6BP7BS2

The NM_020822.3(KCNT1):c.2223C>T(p.Asp741Asp) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000409 in 1,515,894 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000040 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 synonymous

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:3

Conservation

PhyloP100: -1.49

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 -10 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.76).

BP6

Variant 9-135772929-C-T is Benign according to our data. Variant chr9-135772929-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 425468.

BP7

Synonymous conserved (PhyloP=-1.49 with no splicing effect.

BS2

High AC in GnomAd4 at 7 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.2223C>T	p.Asp741Asp	synonymous	Exon 19 of 31	NP_065873.2
	KCNT1	NM_001272003.2		c.2088C>T	p.Asp696Asp	synonymous	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.2223C>T	p.Asp741Asp	synonymous	Exon 19 of 31	ENSP00000360822.2
KCNT1	ENST00000460750.5	TSL:1	n.*1833C>T		non_coding_transcript_exon	Exon 19 of 32	ENSP00000418777.1
KCNT1	ENST00000460750.5	TSL:1	n.*1833C>T		3_prime_UTR	Exon 19 of 32	ENSP00000418777.1

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152148

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.0000941

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000241

AC:

AN:

124630

AF XY:

0.0000149

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000391

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000403

AC:

AN:

1363746

Hom.:

Cov.:

AF XY:

0.0000388

AC XY:

AN XY:

670922

show subpopulations

African (AFR)

AF:

0.0000325

AC:

AN:

30762

American (AMR)

AF:

0.00

AC:

AN:

30302

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

22792

East Asian (EAS)

AF:

0.0000282

AC:

AN:

35482

South Asian (SAS)

AF:

0.0000136

AC:

AN:

73524

European-Finnish (FIN)

AF:

0.00

AC:

AN:

42702

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5422

European-Non Finnish (NFE)

AF:

0.0000469

AC:

AN:

1066316

Other (OTH)

AF:

0.0000354

AC:

AN:

56444

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.504

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:

0.0000460

AC:

AN:

152148

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74304

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41428

American (AMR)

AF:

0.00

AC:

AN:

15278

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.000193

AC:

AN:

5180

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.0000941

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000735

AC:

AN:

68026

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

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:

0.000167

Hom.:

Bravo

AF:

0.0000718

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Jan 01, 2017

CeGaT Center for Human Genetics Tuebingen

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

not specified

Benign:1

Nov 15, 2017

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease.

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

Benign:1

Nov 04, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Inborn genetic diseases

Benign:1

Oct 11, 2016

Ambry Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.76

CADD

Benign

2.5

(source)

DANN

Benign

0.84

PhyloP100

-1.5

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.14

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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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

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over