1-196258199-C-G

Variant names:

• chr1-196258199-C-G
• rs751522470
• NM_198503.5:c.3206G>C

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_198503.5(KCNT2):​c.3206G>C​(p.Gly1069Ala) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,204 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G1069E) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: KCNT2 NM_198503.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 5.83
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• developmental and epileptic encephalopathy, 57

  Inheritance: AD Classification: STRONG, MODERATE, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_198503.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNT2	NM_198503.5	MANE Select	c.3206G>C	p.Gly1069Ala	missense	Exon 26 of 28	NP_940905.2
	KCNT2	NM_001287819.3		c.3134G>C	p.Gly1045Ala	missense	Exon 25 of 27	NP_001274748.1	Q6UVM3-2
	KCNT2	NM_001287820.3		c.3005G>C	p.Gly1002Ala	missense	Exon 25 of 27	NP_001274749.1	Q6UVM3-3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNT2	ENST00000294725.14	TSL:1 MANE Select	c.3206G>C	p.Gly1069Ala	missense	Exon 26 of 28	ENSP00000294725.8	Q6UVM3-1
	KCNT2	ENST00000367433.9	TSL:1	c.3134G>C	p.Gly1045Ala	missense	Exon 25 of 27	ENSP00000356403.5	Q6UVM3-2
	KCNT2	ENST00000609185.5	TSL:1	c.3005G>C	p.Gly1002Ala	missense	Exon 25 of 27	ENSP00000476657.1	Q6UVM3-3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461204 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726932

African (AFR) AF: 0.00 AC: 0 AN: 33464

American (AMR) AF: 0.00 AC: 0 AN: 44702

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26110

East Asian (EAS) AF: 0.00 AC: 0 AN: 39692

South Asian (SAS) AF: 0.00 AC: 0 AN: 86246

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53296

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111562

Other (OTH) AF: 0.00 AC: 0 AN: 60368

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Benign	-0.051	T
BayesDel_noAF	Benign	-0.31
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.29	T
Eigen	Uncertain	0.64
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D
M_CAP	Benign	0.017	T
MetaRNN	Uncertain	0.53	D
MetaSVM	Benign	-1.0	T
MutationAssessor	Uncertain	2.1	M
PhyloP100		5.8
PrimateAI	Pathogenic	0.82	D
PROVEAN	Uncertain	-2.9	D
REVEL	Benign	0.17
Sift	Uncertain	0.021	D
Sift4G	Uncertain	0.031	D
Polyphen		0.40	B
Vest4		0.74
MutPred		0.36		Gain of sheet (P = 0.0344)
MVP		0.11
MPC		1.2
ClinPred		0.99	D
GERP RS		6.0
Varity_R		0.24
gMVP		0.52
Mutation Taster		=38/62	disease causing

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

Other links and lift over

dbSNP: rs751522470; hg19: chr1-196227329;