Genetic Variant KCNT2:p.Ter1136Ter (chr1-196228225-C-T) – ACMG Classification: Benign (-12 pts)

Variant summary

Our verdict is Benign. Variant got -12 ACMG points: 0P and 12B. BP4_ModerateBP6BP7BS1BS2

The NM_198503.5(KCNT2):c.3407G>A(p.Ter1136Ter) variant causes a stop retained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000126 in 1,585,534 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (no stars).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000013 ( 0 hom. )

Consequence

KCNT2
NM_198503.5 stop_retained

Scores

Clinical Significance

Likely benign no assertion criteria provided B:1

Conservation

PhyloP100: 3.15

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 Benign. Variant got -12 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.31).

BP6

Variant 1-196228225-C-T is Benign according to our data. Variant chr1-196228225-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 3057315.Status of the report is no_assertion_criteria_provided, 0 stars.

BP7

Synonymous conserved (PhyloP=3.14 with no splicing effect.

BS1

Variant frequency is greater than expected in population amr. gnomad4_exome allele frequency = 0.0000126 (18/1433472) while in subpopulation AMR AF= 0.000414 (18/43448). AF 95% confidence interval is 0.000268. There are 0 homozygotes in gnomad4_exome. There are 10 alleles in male gnomad4_exome subpopulation. Median coverage is 25. This position pass quality control queck.

BS2

High AC in GnomAdExome4 at 18 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNT2	NM_198503.5 link	c.3407G>A	p.Ter1136Ter	stop_retained_variant	Exon 28 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.3407G>A	p.Ter1136Ter	stop_retained_variant	Exon 28 of 28	1	NM_198503.5	ENSP00000294725.8		Q6UVM3-1

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

152062

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000654

AC:

AN:

244576

Hom.:

AF XY:

0.0000756

AC XY:

AN XY:

132210

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000455

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.000169

GnomAD4 exome

AF:

0.0000126

AC:

AN:

1433472

Hom.:

Cov.:

AF XY:

0.0000140

AC XY:

AN XY:

714350

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000414

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

AF:

0.0000132

AC:

AN:

152062

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74274

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000131

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000378

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: no assertion criteria provided

LINK: link

Submissions by phenotype

KCNT2-related disorder

Benign:1

Feb 18, 2019

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.31

CADD

Benign

8.9

DANN

Benign

0.72

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

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