rs1283268556

Positions:

• chr9-135786483-A-C
• chr9-135786483-A-G

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2 BP4 BP6_Moderate

The ENST00000371757.7(KCNT1):​c.3464A>C​(p.Asn1155Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N1155S) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: KCNT1 ENST00000371757.7 missense
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 9.00

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]

ACMG classification

Verdict is Likely_benign. Variant got -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.2934436).
• BP6: Variant 9-135786483-A-C is Benign according to our data. Variant chr9-135786483-A-C is described in ClinVar as [Likely_benign]. Clinvar id is 540581.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNT1	NM_020822.3	c.3464A>C	p.Asn1155Thr	missense_variant	29/31	ENST00000371757.7	NP_065873.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNT1	ENST00000371757.7	c.3464A>C	p.Asn1155Thr	missense_variant	29/31	1	NM_020822.3	ENSP00000360822	A2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 36

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Developmental and epileptic encephalopathy, 14;C3554306:Autosomal dominant nocturnal frontal lobe epilepsy 5 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 23, 2020

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.37
BayesDel_addAF	Benign	-0.078	T
BayesDel_noAF	Benign	-0.35
CADD	Uncertain	24
DANN	Benign	0.96
DEOGEN2	Benign	0.25	.;.;.;.;.;.;.;.;T;.
Eigen	Benign	-0.11
Eigen_PC	Benign	-0.011
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.92	D;D;D;D;D;D;D;D;D;D
M_CAP	Benign	0.036	D
MetaRNN	Benign	0.29	T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.7	.;.;.;.;.;.;.;.;L;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D
PrimateAI	Pathogenic	0.82	D
PROVEAN	Benign	-2.0	.;.;N;.;.;.;.;.;.;N
REVEL	Benign	0.13
Sift	Benign	0.14	.;.;T;.;.;.;.;.;.;T
Sift4G	Benign	0.33	T;T;T;T;T;T;T;T;T;T
Vest4		0.60
MVP		0.41
MPC		0.099
ClinPred		0.91	D
GERP RS		4.8
Varity_R		0.37
gMVP		0.46

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

Other links and lift over

dbSNP: rs1283268556; hg19: chr9-138678329; COSMIC: COSV53696101; COSMIC: COSV53696101;