9-135775422-C-T

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_020822.3(KCNT1):​c.2349+7C>T variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000497 in 1,604,588 control chromosomes in the GnomAD database, including 16 homozygotes. 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 Benign (★★).

Frequency

Genomes: 𝑓 0.00031 ( 5 hom., cov: 33)
Exomes 𝑓: 0.00052 ( 11 hom. )

Consequence

KCNT1
NM_020822.3 splice_region, intron

Scores

2
Splicing: ADA: 0.0001035
2

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:5

Conservation

PhyloP100: 1.40
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -20 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.6).
BP6
Variant 9-135775422-C-T is Benign according to our data. Variant chr9-135775422-C-T is described in ClinVar as [Benign]. Clinvar id is 241300.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS1
Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.000308 (47/152378) while in subpopulation SAS AF= 0.00952 (46/4834). AF 95% confidence interval is 0.00733. There are 5 homozygotes in gnomad4. There are 36 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.
BS2
High AC in GnomAd4 at 47 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
KCNT1NM_020822.3 linkuse as main transcriptc.2349+7C>T splice_region_variant, intron_variant ENST00000371757.7

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
KCNT1ENST00000371757.7 linkuse as main transcriptc.2349+7C>T splice_region_variant, intron_variant 1 NM_020822.3 A2Q5JUK3-3

Frequencies

GnomAD3 genomes
AF:
0.000309
AC:
47
AN:
152260
Hom.:
5
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00951
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00109
AC:
267
AN:
245480
Hom.:
4
AF XY:
0.00155
AC XY:
205
AN XY:
132684
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000307
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00910
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.000340
GnomAD4 exome
AF:
0.000517
AC:
751
AN:
1452210
Hom.:
11
Cov.:
30
AF XY:
0.000799
AC XY:
577
AN XY:
722356
show subpopulations
Gnomad4 AFR exome
AF:
0.0000300
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00849
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
9.04e-7
Gnomad4 OTH exome
AF:
0.000516
GnomAD4 genome
AF:
0.000308
AC:
47
AN:
152378
Hom.:
5
Cov.:
33
AF XY:
0.000483
AC XY:
36
AN XY:
74510
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.0000653
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00952
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.000167
Hom.:
0
Bravo
AF:
0.0000567
Asia WGS
AF:
0.00404
AC:
14
AN:
3478

ClinVar

Significance: Benign
Submissions summary: Benign:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:1
Benign, criteria provided, single submitterclinical testingGeneDxSep 08, 2016This 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
Benign, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJan 21, 2024- -
not provided Benign:1
Benign, criteria provided, single submitterclinical testingAthena DiagnosticsFeb 28, 2018- -
Developmental and epileptic encephalopathy, 14 Benign:1
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabMar 15, 2022- -
Autosomal dominant nocturnal frontal lobe epilepsy 5 Benign:1
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabMar 15, 2022- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.60
CADD
Benign
4.9
DANN
Benign
0.92

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.00010
dbscSNV1_RF
Benign
0.0020
SpliceAI score (max)
0.010
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.

Other links and lift over

dbSNP: rs190849453; hg19: chr9-138667268; API