9-135702278-C-A

Position:

• chr9-135702278-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_020822.3(KCNT1):​c.20C>A​(p.Ala7Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000687 in 1,456,646 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.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: KCNT1 NM_020822.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.0150

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]

SOHLH1 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.10027152).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNT1	NM_020822.3	c.20C>A	p.Ala7Glu	missense_variant	1/31	ENST00000371757.7	NP_065873.2
KCNT1	NM_001272003.2	c.20C>A	p.Ala7Glu	missense_variant	1/31		NP_001258932.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNT1	ENST00000371757.7	c.20C>A	p.Ala7Glu	missense_variant	1/31	1	NM_020822.3	ENSP00000360822.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.87e-7 AC: 1 AN: 1456646 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 724566

Gnomad4 AFR exome AF: 0.00

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: 0.00

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 33

Bravo AF: 0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 25, 2024

The c.20C>A (p.A7E) alteration is located in exon 1 (coding exon 1) of the KCNT1 gene. This alteration results from a C to A substitution at nucleotide position 20, causing the alanine (A) at amino acid position 7 to be replaced by a glutamic acid (E). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.26	T
BayesDel_noAF	Benign	-0.61
CADD	Benign	17
DANN	Uncertain	0.99
Eigen	Benign	-0.89
Eigen_PC	Benign	-0.93
FATHMM_MKL	Benign	0.14	N
LIST_S2	Benign	0.52	T;T;T
M_CAP	Uncertain	0.22	D
MetaRNN	Benign	0.10	T;T;T
MetaSVM	Benign	-1.1	T
PrimateAI	Uncertain	0.60	T
PROVEAN	Benign	-0.61	N;.;N
REVEL	Benign	0.030
Sift	Pathogenic	0.0	D;.;D
Sift4G	Pathogenic	0.0	D;T;D
Vest4		0.26
MutPred		0.27		Gain of solvent accessibility (P = 0.0068);Gain of solvent accessibility (P = 0.0068);Gain of solvent accessibility (P = 0.0068);
MVP		0.11
MPC		0.75
ClinPred		0.31	T
GERP RS		0.18
gMVP		0.17

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: rs1044336128; hg19: chr9-138594124; COSMIC: COSV100039879; COSMIC: COSV100039879;