rs143536408

chr9-135757192-G-A

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_Strong BP6 BS2

The NM_020822.3(KCNT1):c.637G>A(p.Val213Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000504 in 1,607,604 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00018 (0 hom., cov: 30)
  • Exomes 𝑓: 0.000038 (0 hom.)
• Consequence: KCNT1 NM_020822.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:2
• Conservation: PhyloP100: 0.769

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 -9 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.016379565).
• BP6: Variant 9-135757192-G-A is Benign according to our data. Variant chr9-135757192-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 384598.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=1}.
• BS2: High AC in GnomAd at 27 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNT1	NM_020822.3	c.637G>A	p.Val213Ile	missense_variant	8/31	ENST00000371757.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNT1	ENST00000371757.7	c.637G>A	p.Val213Ile	missense_variant	8/31	1	NM_020822.3	A2

Frequencies

GnomAD3 genomes AF: 0.000184 AC: 27 AN: 146702 Hom.: 0 Cov.: 30

Gnomad AFR AF: 0.000509

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000212

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00987

Gnomad NFE AF: 0.0000149

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000797 AC: 20 AN: 251040 Hom.: 0 AF XY: 0.0000442 AC XY: 6 AN XY: 135758

Gnomad AFR exome AF: 0.000739

Gnomad AMR exome AF: 0.000202

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: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000377 AC: 55 AN: 1460812 Hom.: 0 Cov.: 36 AF XY: 0.0000344 AC XY: 25 AN XY: 726730

Gnomad4 AFR exome AF: 0.000538

Gnomad4 AMR exome AF: 0.000201

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000101

Gnomad4 SAS exome AF: 0.0000464

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000162

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.000177 AC: 26 AN: 146792 Hom.: 0 Cov.: 30 AF XY: 0.000169 AC XY: 12 AN XY: 71196

Gnomad4 AFR AF: 0.000508

Gnomad4 AMR AF: 0.000212

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000149

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000270 Hom.: 0

Bravo AF: 0.000215

ESP6500AA AF: 0.00113 AC: 5

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.0000824 AC: 10

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not specified Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Athena Diagnostics	Aug 26, 2016	- -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Mar 23, 2016	This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

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

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Feb 01, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.054
BayesDel_addAF	Benign	-0.48	T
BayesDel_noAF	Benign	-0.56
Cadd	Benign	1.1
Dann	Benign	0.33
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.072	N
LIST_S2	Uncertain	0.87	D;D;D;D;D;D;D;D;D;D;D
M_CAP	Benign	0.075	D
MetaRNN	Benign	0.016	T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.96	T
MutationTaster	Benign	0.68	N;N;N;N;N;N;N;N
PrimateAI	Uncertain	0.54	T
REVEL	Benign	0.049
Sift4G	Benign	1.0	T;T;T;T;T;T;T;T;T;T;T
Vest4		0.14
MVP		0.15
MPC		0.51
ClinPred		0.016	T
GERP RS		-4.2
Varity_R		0.024
gMVP		0.69

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: rs143536408; hg19: chr9-138649038;