9-135768607-C-T

Variant names:

Variant summary

Our verdict is Benign. Variant got -11 ACMG points: 0P and 11B. BP4_ModerateBP6BS1BS2

The NM_020822.3(KCNT1):c.1338-3C>T variant causes a splice region, intron change. The variant allele was found at a frequency of 0.00028 in 1,550,164 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00030 ( 0 hom., cov: 30)

Exomes 𝑓: 0.00028 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 splice_region, intron

Scores

Splicing: ADA: 0.06911

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:4

Conservation

PhyloP100: 3.83

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 -11 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.23).

BP6

Variant 9-135768607-C-T is Benign according to our data. Variant chr9-135768607-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 389495.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Benign=3, Uncertain_significance=1}. Variant chr9-135768607-C-T is described in Lovd as [Likely_benign].

BS1

Variant frequency is greater than expected in population amr. gnomad4 allele frequency = 0.000302 (46/152176) while in subpopulation AMR AF= 0.000981 (15/15288). AF 95% confidence interval is 0.000604. There are 0 homozygotes in gnomad4. There are 23 alleles in male gnomad4 subpopulation. Median coverage is 30. This position pass quality control queck.

BS2

High AC in GnomAd4 at 46 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNT1	NM_020822.3 link	c.1338-3C>T		splice_region_variant, intron_variant	Intron 13 of 30	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.1338-3C>T		splice_region_variant, intron_variant	Intron 13 of 30	1	NM_020822.3	ENSP00000360822.2		Q5JUK3-3

Frequencies

GnomAD3 genomes

AF:

0.000303

AC:

AN:

152058

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000982

Gnomad ASJ

AF:

0.00144

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000338

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.000340

AC:

AN:

155700

Hom.:

AF XY:

0.000354

AC XY:

AN XY:

82018

show subpopulations

Gnomad AFR exome

AF:

0.000115

Gnomad AMR exome

AF:

0.000606

Gnomad ASJ exome

AF:

0.000707

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000176

Gnomad FIN exome

AF:

0.000130

Gnomad NFE exome

AF:

0.000317

Gnomad OTH exome

AF:

0.00136

GnomAD4 exome

AF:

0.000278

AC:

388

AN:

1397988

Hom.:

Cov.:

AF XY:

0.000283

AC XY:

195

AN XY:

689576

show subpopulations

Gnomad4 AFR exome

AF:

0.0000633

Gnomad4 AMR exome

AF:

0.000644

Gnomad4 ASJ exome

AF:

0.000756

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000101

Gnomad4 FIN exome

AF:

0.0000414

Gnomad4 NFE exome

AF:

0.000287

Gnomad4 OTH exome

AF:

0.000397

GnomAD4 genome

AF:

0.000302

AC:

AN:

152176

Hom.:

Cov.:

AF XY:

0.000309

AC XY:

AN XY:

74400

show subpopulations

Gnomad4 AFR

AF:

0.0000482

Gnomad4 AMR

AF:

0.000981

Gnomad4 ASJ

AF:

0.00144

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000338

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.000444

Hom.:

Bravo

AF:

0.000355

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:4

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1Benign:1

Dec 31, 2020

GeneDx

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Sep 01, 2016

CeGaT Center for Human Genetics Tuebingen

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not specified

Benign:1

Jun 26, 2017

Athena Diagnostics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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

Benign:1

Feb 03, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Inborn genetic diseases

Benign:1

Jun 22, 2023

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 v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.23

CADD

Benign

DANN

Benign

0.96

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.069

dbscSNV1_RF

Benign

0.088

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

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