rs368480443

Variant summary

Our verdict is Benign. The variant received -13 ACMG points: 0P and 13B. BP4_StrongBP6BS1BS2

The NM_020822.3(KCNT1):​c.1511-4G>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000426 in 1,548,486 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 0.00022 ( 0 hom., cov: 34)
Exomes 𝑓: 0.000024 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 splice_region, intron

Scores

2
Splicing: ADA: 0.0004899
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:2

Conservation

PhyloP100: -0.281

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -13 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.74).
BP6
Variant 9-135769943-G-A is Benign according to our data. Variant chr9-135769943-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 417217.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000217 (33/152194) while in subpopulation AFR AF = 0.000652 (27/41432). AF 95% confidence interval is 0.00046. There are 0 homozygotes in GnomAd4. There are 19 alleles in the male GnomAd4 subpopulation. Median coverage is 34. This position passed quality control check.
BS2
High AC in GnomAd4 at 33 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNT1NM_020822.3 linkc.1511-4G>A splice_region_variant, intron_variant Intron 15 of 30 ENST00000371757.7 NP_065873.2 Q5JUK3-3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNT1ENST00000371757.7 linkc.1511-4G>A splice_region_variant, intron_variant Intron 15 of 30 1 NM_020822.3 ENSP00000360822.2 Q5JUK3-3

Frequencies

GnomAD3 genomes
AF:
0.000217
AC:
33
AN:
152194
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.000652
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:
0.0000294
Gnomad OTH
AF:
0.000479
GnomAD2 exomes
AF:
0.0000458
AC:
7
AN:
152826
AF XY:
0.0000496
show subpopulations
Gnomad AFR exome
AF:
0.000462
Gnomad AMR exome
AF:
0.0000809
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000174
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000236
AC:
33
AN:
1396292
Hom.:
0
Cov.:
31
AF XY:
0.0000203
AC XY:
14
AN XY:
688838
show subpopulations
African (AFR)
AF:
0.000349
AC:
11
AN:
31548
American (AMR)
AF:
0.0000839
AC:
3
AN:
35752
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25100
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35760
South Asian (SAS)
AF:
0.0000253
AC:
2
AN:
79122
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
48058
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5320
European-Non Finnish (NFE)
AF:
0.0000130
AC:
14
AN:
1077736
Other (OTH)
AF:
0.0000518
AC:
3
AN:
57896
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.523
Heterozygous variant carriers
0
2
4
6
8
10
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.000217
AC:
33
AN:
152194
Hom.:
0
Cov.:
34
AF XY:
0.000256
AC XY:
19
AN XY:
74354
show subpopulations
African (AFR)
AF:
0.000652
AC:
27
AN:
41432
American (AMR)
AF:
0.000196
AC:
3
AN:
15292
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4838
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68024
Other (OTH)
AF:
0.000479
AC:
1
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.513
Heterozygous variant carriers
0
2
4
6
8
10
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.000174
Hom.:
0
Bravo
AF:
0.000208

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Aug 11, 2016
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1511-4G>A intronic variant results from a G to A substitution 4 nucleotides upstream from coding exon 16 in the KCNT1 gene. This variant was previously reported in the SNPDatabase as rs368480443. Based on data from the NHLBI Exome Sequencing Project (ESP), the A allele has an overall frequency of approximately 0.03% (4/12452) total alleles studied, having been observed in 0.07% (3/4204) African American alleles and 0.01% (1/8248) European American alleles. This nucleotide position is poorly conserved in available vertebrate species. Using the BDGP and ESEfinder splice site prediction tools, this alteration is not predicted to have any significant effect on this splice acceptor site; however, direct evidence is unavailable. Since supporting evidence is limited at this time, the clinical significance of this variant remains unclear. -

Developmental and epileptic encephalopathy, 14;C3554306:Autosomal dominant nocturnal frontal lobe epilepsy 5 Benign:1
Nov 06, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Benign:1
Jun 05, 2018
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.74
CADD
Benign
4.8
DANN
Benign
0.85
PhyloP100
-0.28

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.00049
dbscSNV1_RF
Benign
0.016
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

Other links and lift over

dbSNP: rs368480443; hg19: chr9-138661789; COSMIC: COSV53704943; COSMIC: COSV53704943; API