rs754629346

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM4BS2

The NM_020822.3(KCNT1):​c.2061_2066delCGGTGG​(p.Gly688_Gly689del) variant causes a disruptive inframe deletion change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000366 in 1,476,612 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. G687G) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000036 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 disruptive_inframe_deletion

Scores

Not classified

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:2

Conservation

PhyloP100: 2.79

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

PM4
Nonframeshift variant in NON repetitive region in NM_020822.3.
BS2
High AC in GnomAd4 at 6 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.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNT1
NM_020822.3
MANE Select
c.2061_2066delCGGTGGp.Gly688_Gly689del
disruptive_inframe_deletion
Exon 19 of 31NP_065873.2Q5JUK3-3
KCNT1
NM_001272003.2
c.1926_1931delCGGTGGp.Gly643_Gly644del
disruptive_inframe_deletion
Exon 18 of 31NP_001258932.1Q5JUK3-4

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNT1
ENST00000371757.7
TSL:1 MANE Select
c.2061_2066delCGGTGGp.Gly688_Gly689del
disruptive_inframe_deletion
Exon 19 of 31ENSP00000360822.2Q5JUK3-3
KCNT1
ENST00000460750.5
TSL:1
n.*1671_*1676delCGGTGG
non_coding_transcript_exon
Exon 19 of 32ENSP00000418777.1F8WC49
KCNT1
ENST00000460750.5
TSL:1
n.*1671_*1676delCGGTGG
3_prime_UTR
Exon 19 of 32ENSP00000418777.1F8WC49

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152206
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.0000882
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000236
AC:
2
AN:
84786
AF XY:
0.0000227
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000712
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000362
AC:
48
AN:
1324406
Hom.:
0
AF XY:
0.0000449
AC XY:
29
AN XY:
645482
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
29266
American (AMR)
AF:
0.00
AC:
0
AN:
25348
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
20476
East Asian (EAS)
AF:
0.00
AC:
0
AN:
33958
South Asian (SAS)
AF:
0.00
AC:
0
AN:
67132
European-Finnish (FIN)
AF:
0.0000221
AC:
1
AN:
45190
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5328
European-Non Finnish (NFE)
AF:
0.0000441
AC:
46
AN:
1042918
Other (OTH)
AF:
0.0000183
AC:
1
AN:
54790
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.452
Heterozygous variant carriers
0
3
6
10
13
16
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:
0.0000394
AC:
6
AN:
152206
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74346
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41454
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000882
AC:
6
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
1
2
2
3
4
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:
0.000108
Hom.:
0
Bravo
AF:
0.0000189

ClinVar

ClinVar submissions
Significance:Conflicting classifications of pathogenicity
Revision:criteria provided, conflicting classifications
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
-
2
not provided (2)
-
1
-
Developmental and epileptic encephalopathy, 14;C3554306:Autosomal dominant nocturnal frontal lobe epilepsy 5 (1)
-
1
-
KCNT1-related disorder (1)
-
1
-
not specified (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
PhyloP100
2.8
Mutation Taster
=162/38
polymorphism

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs754629346; hg19: chr9-138664610; API