9-135786336-G-T

Variant names:

• chr9-135786336-G-T
• rs561255614
• NM_020822.3:c.3317G>T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PP3_Moderate BS2

The NM_020822.3(KCNT1):​c.3317G>T​(p.Arg1106Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000694 in 1,441,676 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000069 (0 hom.)
• Consequence: KCNT1 NM_020822.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.18

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 -2 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.898
• BS2: High AC in GnomAdExome4 at 10 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNT1	NM_020822.3	c.3317G>T	p.Arg1106Leu	missense_variant	Exon 29 of 31	ENST00000371757.7	NP_065873.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNT1	ENST00000371757.7	c.3317G>T	p.Arg1106Leu	missense_variant	Exon 29 of 31	1	NM_020822.3	ENSP00000360822.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.0000151 AC: 3 AN: 198616 Hom.: 0 AF XY: 0.0000182 AC XY: 2 AN XY: 109752

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000358

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000694 AC: 10 AN: 1441676 Hom.: 0 Cov.: 36 AF XY: 0.00000559 AC XY: 4 AN XY: 715244

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: 0.00000906

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.0000351 AC: 4

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.58
BayesDel_addAF	Uncertain	0.028	T
BayesDel_noAF	Benign	-0.090
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.26	.;.;.;.;.;.;.;.;T;.
Eigen	Uncertain	0.60
Eigen_PC	Uncertain	0.50
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	1.0	D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.87	D
MetaRNN	Pathogenic	0.90	D;D;D;D;D;D;D;D;D;D
MetaSVM	Benign	-0.42	T
MutationAssessor	Uncertain	2.3	.;.;.;.;.;.;.;.;M;.
PrimateAI	Uncertain	0.70	T
PROVEAN	Uncertain	-3.2	.;.;D;.;.;.;.;.;.;D
REVEL	Uncertain	0.36
Sift	Pathogenic	0.0	.;.;D;.;.;.;.;.;.;D
Sift4G	Uncertain	0.0020	D;D;D;D;D;D;D;D;D;D
Vest4		0.80
MVP		0.61
MPC		0.50
ClinPred		0.98	D
GERP RS		4.8
Varity_R		0.40
gMVP		0.62

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: rs561255614; hg19: chr9-138678182;