NM_020822.3:c.1614C>T

Variant names:

Variant summary

Our verdict is Benign. Variant got -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_020822.3(KCNT1):c.1614C>T(p.Arg538Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000942 in 1,549,910 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.000079 ( 0 hom., cov: 34)

Exomes 𝑓: 0.000096 ( 2 hom. )

Consequence

KCNT1
NM_020822.3 synonymous

Scores

Clinical Significance

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

Conservation

PhyloP100: -2.05

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -21 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.75).

BP6

Variant 9-135770050-C-T is Benign according to our data. Variant chr9-135770050-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 383992.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr9-135770050-C-T is described in Lovd as [Likely_benign].

BP7

Synonymous conserved (PhyloP=-2.05 with no splicing effect.

BS1

Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.0000788 (12/152340) while in subpopulation SAS AF= 0.00124 (6/4834). AF 95% confidence interval is 0.00054. There are 0 homozygotes in gnomad4. There are 6 alleles in male gnomad4 subpopulation. Median coverage is 34. This position pass quality control queck.

BS2

High AC in GnomAd4 at 12 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNT1	NM_020822.3 link	c.1614C>T	p.Arg538Arg	synonymous_variant	Exon 16 of 31	ENST00000371757.7	NP_065873.2	Q5JUK3-3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNT1	ENST00000371757.7 link	c.1614C>T	p.Arg538Arg	synonymous_variant	Exon 16 of 31	1	NM_020822.3	ENSP00000360822.2		Q5JUK3-3

Frequencies

GnomAD3 genomes

AF:

0.0000854

AC:

AN:

152222

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000965

Gnomad SAS

AF:

0.00124

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.000378

AC:

AN:

153406

Hom.:

AF XY:

0.000345

AC XY:

AN XY:

81108

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000402

Gnomad ASJ exome

AF:

0.000120

Gnomad EAS exome

AF:

0.00290

Gnomad SAS exome

AF:

0.000790

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000173

Gnomad OTH exome

AF:

0.000920

GnomAD4 exome

AF:

0.0000959

AC:

134

AN:

1397570

Hom.:

Cov.:

AF XY:

0.000104

AC XY:

AN XY:

689524

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000278

Gnomad4 ASJ exome

AF:

0.0000398

Gnomad4 EAS exome

AF:

0.000949

Gnomad4 SAS exome

AF:

0.000909

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000463

Gnomad4 OTH exome

AF:

0.000363

GnomAD4 genome

AF:

0.0000788

AC:

AN:

152340

Hom.:

Cov.:

AF XY:

0.0000806

AC XY:

AN XY:

74480

show subpopulations

Gnomad4 AFR

AF:

0.0000240

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000773

Gnomad4 SAS

AF:

0.00124

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.0000831

Asia WGS

AF:

0.00144

AC:

AN:

3478

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

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

Benign:1

Oct 21, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

KCNT1-related disorder

Benign:1

Apr 01, 2019

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Developmental and epileptic encephalopathy, 14

Benign:1

Mar 15, 2022

Genome-Nilou Lab

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Benign:1

Nov 03, 2020

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Autosomal dominant nocturnal frontal lobe epilepsy 5

Benign:1

Mar 15, 2022

Genome-Nilou Lab

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.75

CADD

Benign

5.0

DANN

Benign

0.92

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over