rs141521745

Variant names:

• chr9-135792143-C-A
• rs141521745
• NM_020822.3:c.3690C>A

Your query was ambiguous. Multiple possible variants found:

• chr9-135792143-C-A
• chr9-135792143-C-T

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_Strong BP7 BS2

The ENST00000371757.7(KCNT1):​c.3690C>A​(p.Arg1230Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000162 in 1,605,710 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. R1230R) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000017 (0 hom.)
• Consequence: KCNT1 ENST00000371757.7 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -2.42
• Publications: 0 publications found

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]

KCNT1 Gene-Disease associations (from GenCC):

• childhood-onset epilepsy syndrome

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• developmental and epileptic encephalopathy, 14

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
• malignant migrating partial seizures of infancy

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Orphanet
• autosomal dominant nocturnal frontal lobe epilepsy 5

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• autosomal dominant nocturnal frontal lobe epilepsy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

LOC107987140 (HGNC:):

ACMG classification

Our verdict: Benign. The variant received -9 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.94).
• BP7: Synonymous conserved (PhyloP=-2.42 with no splicing effect.
• BS2: High AC in GnomAdExome4 at 24 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: ENST00000371757.7. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNT1	NM_020822.3	MANE Select	c.3690C>A	p.Arg1230Arg	synonymous	Exon 31 of 31	NP_065873.2
	KCNT1	NM_001272003.2		c.3618C>A	p.Arg1206Arg	synonymous	Exon 31 of 31	NP_001258932.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNT1	ENST00000371757.7	TSL:1 MANE Select	c.3690C>A	p.Arg1230Arg	synonymous	Exon 31 of 31	ENSP00000360822.2
	KCNT1	ENST00000460750.5	TSL:1	n.*3363C>A		non_coding_transcript_exon	Exon 32 of 32	ENSP00000418777.1
	KCNT1	ENST00000460750.5	TSL:1	n.*3363C>A		3_prime_UTR	Exon 32 of 32	ENSP00000418777.1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152104 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000125 AC: 3 AN: 240750 AF XY: 0.00000761

Gnomad AFR exome AF: 0.000127

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS 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: 0.0000165 AC: 24 AN: 1453606 Hom.: 0 Cov.: 32 AF XY: 0.0000124 AC XY: 9 AN XY: 723388

African (AFR) AF: 0.0000896 AC: 3 AN: 33466

American (AMR) AF: 0.00 AC: 0 AN: 44598

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26078

East Asian (EAS) AF: 0.00 AC: 0 AN: 39666

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86004

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 46146

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.0000180 AC: 20 AN: 1111580

Other (OTH) AF: 0.00 AC: 0 AN: 60302

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152104 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74292

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000241 AC: 1 AN: 41416

American (AMR) AF: 0.0000654 AC: 1 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5170

South Asian (SAS) AF: 0.00 AC: 0 AN: 4816

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10624

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68012

Other (OTH) AF: 0.00 AC: 0 AN: 2088

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.00000000770867), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 2

Bravo AF: 0.0000113

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.94
CADD	Benign	0.022
DANN	Benign	0.54
PhyloP100		-2.4

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: rs141521745; hg19: chr9-138683989;