Genetic Variant KCNT2:p.Asp1097Asn (chr1-196235993-C-T) – ACMG Classification: Uncertain_significance (3 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP3

The NM_198503.5(KCNT2):c.3289G>A(p.Asp1097Asn) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

KCNT2
NM_198503.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 5.33

Variant links:

Genes affected

KCNT2 (HGNC:18866): (potassium sodium-activated channel subfamily T member 2) Enables chloride-activated potassium channel activity. Involved in potassium ion export across plasma membrane. Located in plasma membrane. Implicated in developmental and epileptic encephalopathy 57. [provided by Alliance of Genome Resources, Apr 2022]

KCNT2 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.832

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNT2	NM_198503.5 link	c.3289G>A	p.Asp1097Asn	missense_variant	Exon 27 of 28	ENST00000294725.14	NP_940905.2	Q6UVM3-1A9LNM6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNT2	ENST00000294725.14 link	c.3289G>A	p.Asp1097Asn	missense_variant	Exon 27 of 28	1	NM_198503.5	ENSP00000294725.8		Q6UVM3-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

Data not reliable, filtered out with message: AC0

AF:

0.00

AC:

AN:

1431532

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

714040

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy, 57

Uncertain:1

Jun 11, 2020

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.1.1, this variant is classified as 3C-VUS. Following criteria are met: 0103 - Both loss- and gain-of-function are known mechanisms of disease for this gene. Gain of function, loss of function, change of function, and the possibility of a dominant negative mechanism, have all been reported for pathogenic KCNT2 variants in patients with early-onset epileptic encephalopathies, including epilepsy of infancy with migrating focal seizures (PMID: 29069600, PMID: 29740868, PMID: 32038177). (N) 0107 - This gene is known to be associated with autosomal dominant disease. (N) 0200 - Variant is predicted to result in a missense amino acid change from aspartic acid to asparagine (exon 27). (N) 0251 - Variant is heterozygous. (N) 0301 - Variant is absent from gnomAD. (P) 0504 - Same amino acid change has been observed in mammals. (B) 0604 - Variant is not located in an established domain, motif, hotspot or informative constraint region. (N) 0705 - No comparable variants have previous evidence for pathogenicity. (N) 0807 - Variant has not previously been reported in a clinical context. (N) 0905 - No segregation evidence has been identified for this variant. (N) 1007 - No published functional evidence has been identified for this variant. (N) 1208 - Inheritance information for this variant is not currently available. (N) Legend: (P) - Pathogenic, (N) - Neutral, (B) - Benign -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.96

BayesDel_addAF

Benign

-0.053

BayesDel_noAF

Benign

-0.31

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.44

.;.;T

Eigen

Pathogenic

0.84

Eigen_PC

Pathogenic

0.80

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Pathogenic

1.0

D;D;D

M_CAP

Uncertain

0.24

MetaRNN

Pathogenic

0.83

D;D;D

MetaSVM

Uncertain

0.068

MutationAssessor

Uncertain

2.5

.;.;M

PrimateAI

Uncertain

0.75

PROVEAN

Uncertain

-4.2

D;.;D

REVEL

Uncertain

0.48

Sift

Pathogenic

0.0

D;.;D

Sift4G

Pathogenic

0.0

D;D;D

Polyphen

1.0

D;D;D

Vest4

0.82

MutPred

0.67

.;.;Loss of sheet (P = 0.0457);

MVP

0.32

MPC

1.2

ClinPred

1.0

GERP RS

5.7

Varity_R

0.76

gMVP

0.90

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

No publications associated with this variant yet.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over