rs113333501

Positions:

• chr9-135770008-G-A

Variant summary

Our verdict is Benign. Variant got -17 ACMG points: 0P and 17B. BP4_Strong BP6_Very_Strong BP7 BS2

The NM_020822.3(KCNT1):​c.1572G>A​(p.Pro524=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000491 in 1,404,768 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.000049 (1 hom.)
• Consequence: KCNT1 NM_020822.3 synonymous
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:4
• Conservation: PhyloP100: -3.01

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 Benign. Variant got -17 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.55).
• BP6: Variant 9-135770008-G-A is Benign according to our data. Variant chr9-135770008-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 540559.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=-3.01 with no splicing effect.
• BS2: High AC in GnomAdExome4 at 69 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNT1	NM_020822.3	c.1572G>A	p.Pro524=	synonymous_variant	16/31	ENST00000371757.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNT1	ENST00000371757.7	c.1572G>A	p.Pro524=	synonymous_variant	16/31	1	NM_020822.3	A2

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD3 exomes AF: 0.00000610 AC: 1 AN: 163950 Hom.: 0 AF XY: 0.0000115 AC XY: 1 AN XY: 86884

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: 0.0000155

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000491 AC: 69 AN: 1404768 Hom.: 1 Cov.: 32 AF XY: 0.0000533 AC XY: 37 AN XY: 693588

Gnomad4 AFR exome AF: 0.000251

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: 0.0000388

Gnomad4 OTH exome AF: 0.000292

GnomAD4 genome Cov.: 34

Alfa AF: 0.0000282 Hom.: 0

Bravo AF: 0.0000264

ClinVar

Significance: Likely benign

Submissions summary: Benign:4

Revision: criteria provided, multiple submitters, no conflicts

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

Aug 24, 2023

- -

not provided Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

May 14, 2019

- -

Developmental and epileptic encephalopathy, 14 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Mar 15, 2022

- -

Autosomal dominant nocturnal frontal lobe epilepsy 5 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Mar 15, 2022

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.55
CADD	Benign	12
DANN	Benign	0.92

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs113333501; hg19: chr9-138661854; COSMIC: COSV104556745; COSMIC: COSV104556745;