Genetic Variant KCNT1:p.Tyr575Tyr (chr9-135770403-C-T) – ACMG Classification: Benign (-19 pts)

Variant summary

Our verdict is Benign. The variant received -19 ACMG points: 0P and 19B. BP4_ModerateBP6_Very_StrongBP7BS1BS2

The NM_020822.3(KCNT1):c.1725C>T(p.Tyr575Tyr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000125 in 1,613,058 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 Likely benign (★★).

Frequency

Genomes: 𝑓 0.000092 ( 0 hom., cov: 34)

Exomes 𝑓: 0.00013 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 synonymous

Scores

Clinical Significance

Likely benign criteria provided, multiple submitters, no conflicts B:6

Conservation

PhyloP100: 0.121

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:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -19 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.42).

BP6

Variant 9-135770403-C-T is Benign according to our data. Variant chr9-135770403-C-T is described in ClinVar as Likely_benign. ClinVar VariationId is 386463.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BP7

Synonymous conserved (PhyloP=0.121 with no splicing effect.

BS1

Variant frequency is greater than expected in population mid. GnomAdExome4 allele frequency = 0.000129 (188/1460858) while in subpopulation MID AF = 0.00104 (6/5766). AF 95% confidence interval is 0.000453. There are 0 homozygotes in GnomAdExome4. There are 95 alleles in the male GnomAdExome4 subpopulation. Median coverage is 31. This position passed quality control check.

BS2

High AC in GnomAd4 at 14 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.1725C>T	p.Tyr575Tyr	synonymous	Exon 17 of 31	NP_065873.2	Q5JUK3-3
	KCNT1	NM_001272003.2		c.1590C>T	p.Tyr530Tyr	synonymous	Exon 16 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.1725C>T	p.Tyr575Tyr	synonymous	Exon 17 of 31	ENSP00000360822.2	Q5JUK3-3
KCNT1	ENST00000460750.5	TSL:1	n.*1335C>T		non_coding_transcript_exon	Exon 17 of 32	ENSP00000418777.1	F8WC49
KCNT1	ENST00000460750.5	TSL:1	n.*1335C>T		3_prime_UTR	Exon 17 of 32	ENSP00000418777.1	F8WC49

Frequencies

GnomAD3 genomes

AF:

0.0000920

AC:

AN:

152200

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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:

0.000132

Gnomad OTH

AF:

0.000956

GnomAD2 exomes

AF:

0.000152

AC:

AN:

250604

AF XY:

0.000207

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000145

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000150

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000129

AC:

188

AN:

1460858

Hom.:

Cov.:

AF XY:

0.000131

AC XY:

AN XY:

726784

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33468

American (AMR)

AF:

0.000157

AC:

AN:

44688

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26082

East Asian (EAS)

AF:

0.00

AC:

AN:

39692

South Asian (SAS)

AF:

0.000522

AC:

AN:

86226

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52892

Middle Eastern (MID)

AF:

0.00104

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.000107

AC:

119

AN:

1111696

Other (OTH)

AF:

0.000166

AC:

AN:

60348

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:

0.0000920

AC:

AN:

152200

Hom.:

Cov.:

AF XY:

0.000108

AC XY:

AN XY:

74352

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41438

American (AMR)

AF:

0.000131

AC:

AN:

15284

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5192

South Asian (SAS)

AF:

0.00

AC:

AN:

4838

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10626

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000132

AC:

AN:

68032

Other (OTH)

AF:

0.000956

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.482

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:

0.000114

Hom.:

Bravo

AF:

0.0000680

Asia WGS

AF:

0.000577

AC:

AN:

3478

EpiCase

AF:

0.000218

EpiControl

AF:

0.000178

ClinVar

ClinVar submissions

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)

not specified (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.42

CADD

Benign

(source)

DANN

Benign

0.96

PhyloP100

0.12

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