rs1182743416

chr9-135786447-G-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4 BP6

The NM_020822.3(KCNT1):c.3428G>A(p.Arg1143His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000159 in 1,446,354 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1143C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000016 (0 hom.)
• Consequence: KCNT1 NM_020822.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 7.84

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.

• BP4: Computational evidence support a benign effect (MetaRNN=0.40028757).
• BP6: Variant 9-135786447-G-A is Benign according to our data. Variant chr9-135786447-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 540582.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNT1	NM_020822.3	c.3428G>A	p.Arg1143His	missense_variant	29/31	ENST00000371757.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNT1	ENST00000371757.7	c.3428G>A	p.Arg1143His	missense_variant	29/31	1	NM_020822.3	A2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.0000159 AC: 23 AN: 1446354 Hom.: 0 Cov.: 36 AF XY: 0.0000181 AC XY: 13 AN XY: 718730

Gnomad4 AFR exome AF: 0.0000304

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000256

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000181

Gnomad4 OTH exome AF: 0.0000168

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genomic Research Center, Shahid Beheshti University of Medical Sciences

May 03, 2020

- -

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

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Jun 10, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.24
BayesDel_addAF	Benign	0.0026	T
BayesDel_noAF	Benign	-0.23
Cadd	Uncertain	26
Dann	Uncertain	1.0
Eigen	Uncertain	0.46
Eigen_PC	Uncertain	0.35
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.10	D
MetaRNN	Benign	0.40	T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.75	T
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.57	T
REVEL	Uncertain	0.36
Sift4G	Uncertain	0.020	D;D;T;D;D;D;T;D;D;D
Vest4		0.51
MVP		0.71
MPC		0.12
ClinPred		0.95	D
GERP RS		4.8
Varity_R		0.17
gMVP		0.36

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: rs1182743416; hg19: chr9-138678293;