rs759060691

chr9-135786316-C-Gchr9-135786316-C-T

Variant summary

Our verdict is Benign. Variant got -11 ACMG points: 2P and 13B. PM2 BP4_Strong BP6_Very_Strong BP7

The NM_020822.3(KCNT1):c.3297C>G(p.Pro1099=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000138 in 1,447,806 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 (★★). Synonymous variant affecting the same amino acid position (i.e. P1099P) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: KCNT1 NM_020822.3 synonymous
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:4
• Conservation: PhyloP100: -0.428

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 -11 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.84).
• BP6: Variant 9-135786316-C-G is Benign according to our data. Variant chr9-135786316-C-G is described in ClinVar as [Likely_benign]. Clinvar id is 473385.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=-0.428 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNT1	NM_020822.3	c.3297C>G	p.Pro1099=	synonymous_variant	29/31	ENST00000371757.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNT1	ENST00000371757.7	c.3297C>G	p.Pro1099=	synonymous_variant	29/31	1	NM_020822.3	A2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000964 AC: 2 AN: 207550 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 114748

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000639

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: 0.00

GnomAD4 exome AF: 0.00000138 AC: 2 AN: 1447806 Hom.: 0 Cov.: 36 AF XY: 0.00000139 AC XY: 1 AN XY: 719002

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000469

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 Cov.: 33

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

Invitae

Oct 09, 2020

- -

not provided Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Apr 09, 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	-0.84
Cadd	Benign	0.045
Dann	Benign	0.41

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: rs759060691; hg19: chr9-138678162;