dbSNP rs141521745: KCNT1:p.Arg1230Arg (chr9-135792143-C-T) – ACMG Classification: Benign (-21 pts)

Variant summary

Our verdict is Benign. The variant received -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_020822.3(KCNT1):c.3690C>T(p.Arg1230Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000395 in 1,605,818 control chromosomes in the GnomAD database, including 3 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0019 ( 1 hom., cov: 33)

Exomes 𝑓: 0.00023 ( 2 hom. )

Consequence

KCNT1
NM_020822.3 synonymous

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:9

Conservation

PhyloP100: -2.42

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: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
malignant migrating partial seizures of infancy
Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, G2P
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:

LOC107987140 (HGNC:):

LOC107987140 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -21 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.95).

BP6

Variant 9-135792143-C-T is Benign according to our data. Variant chr9-135792143-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 289215.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BP7

Synonymous conserved (PhyloP=-2.42 with no splicing effect.

BS1

Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00194 (296/152216) while in subpopulation AFR AF = 0.00684 (284/41534). AF 95% confidence interval is 0.00618. There are 1 homozygotes in GnomAd4. There are 123 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.

BS2

High AC in GnomAd4 at 296 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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNT1	NM_020822.3	MANE Select	c.3690C>T	p.Arg1230Arg	synonymous	Exon 31 of 31	NP_065873.2	Q5JUK3-3
	KCNT1	NM_001272003.2		c.3618C>T	p.Arg1206Arg	synonymous	Exon 31 of 31	NP_001258932.1	Q5JUK3-4

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
KCNT1	ENST00000371757.7	TSL:1 MANE Select	c.3690C>T	p.Arg1230Arg	synonymous	Exon 31 of 31	ENSP00000360822.2	Q5JUK3-3
KCNT1	ENST00000460750.5	TSL:1	n.*3363C>T		non_coding_transcript_exon	Exon 32 of 32	ENSP00000418777.1	F8WC49
KCNT1	ENST00000460750.5	TSL:1	n.*3363C>T		3_prime_UTR	Exon 32 of 32	ENSP00000418777.1	F8WC49

Frequencies

GnomAD3 genomes

AF:

0.00195

AC:

296

AN:

152098

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00686

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

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:

0.000118

Gnomad OTH

AF:

0.000479

GnomAD2 exomes

AF:

0.000565

AC:

136

AN:

240750

AF XY:

0.000449

show subpopulations

Gnomad AFR exome

AF:

0.00807

Gnomad AMR exome

AF:

0.0000292

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000548

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000544

Gnomad OTH exome

AF:

0.000167

GnomAD4 exome

AF:

0.000233

AC:

339

AN:

1453602

Hom.:

Cov.:

AF XY:

0.000213

AC XY:

154

AN XY:

723386

show subpopulations

African (AFR)

AF:

0.00789

AC:

264

AN:

33464

American (AMR)

AF:

0.0000673

AC:

AN:

44598

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26078

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39666

South Asian (SAS)

AF:

0.00

AC:

AN:

86004

European-Finnish (FIN)

AF:

0.00

AC:

AN:

46144

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.0000486

AC:

AN:

1111580

Other (OTH)

AF:

0.000282

AC:

AN:

60302

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.467

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

100

<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:

0.00194

AC:

296

AN:

152216

Hom.:

Cov.:

AF XY:

0.00165

AC XY:

123

AN XY:

74420

show subpopulations

African (AFR)

AF:

0.00684

AC:

284

AN:

41534

American (AMR)

AF:

0.000196

AC:

AN:

15300

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5156

South Asian (SAS)

AF:

0.00

AC:

AN:

4812

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000118

AC:

AN:

68004

Other (OTH)

AF:

0.000474

AC:

AN:

2110

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.492

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Genome Hom

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:

0.000706

Hom.:

Bravo

AF:

0.00215

Asia WGS

AF:

0.000866

AC:

AN:

3478

EpiCase

AF:

0.0000545

EpiControl

AF:

0.0000594

ClinVar

ClinVar submissions

Significance:Benign/Likely benign

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

not provided (2)

not specified (2)

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)

KCNT1-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.95

CADD

Benign

0.94

(source)

DANN

Benign

0.71

PhyloP100

-2.4

Mutation Taster

=100/0

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

Computational scores

Splicing

Publications

Other links and lift over