1-154713478-C-T

Variant names:

• chr1-154713478-C-T
• rs1557937420
• NM_002249.6:c.1885G>A

Variant summary

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

The NM_002249.6(KCNN3):​c.1885G>A​(p.Val629Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: KCNN3 NM_002249.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.40

Genes affected

KCNN3 (HGNC:6292): (potassium calcium-activated channel subfamily N member 3) Action potentials in vertebrate neurons are followed by an afterhyperpolarization (AHP) that may persist for several seconds and may have profound consequences for the firing pattern of the neuron. Each component of the AHP is kinetically distinct and is mediated by different calcium-activated potassium channels. This gene belongs to the KCNN family of potassium channels. It encodes an integral membrane protein that forms a voltage-independent calcium-activated channel, which is thought to regulate neuronal excitability by contributing to the slow component of synaptic AHP. This gene contains two CAG repeat regions in the coding sequence. It was thought that expansion of one or both of these repeats could lead to an increased susceptibility to schizophrenia or bipolar disorder, but studies indicate that this is probably not the case. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Feb 2011]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNN3	NM_002249.6	c.1885G>A	p.Val629Met	missense_variant	Exon 7 of 8	ENST00000271915.9	NP_002240.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNN3	ENST00000271915.9	c.1885G>A	p.Val629Met	missense_variant	Exon 7 of 8	1	NM_002249.6	ENSP00000271915.3
KCNN3	ENST00000361147.8	c.970G>A	p.Val324Met	missense_variant	Exon 7 of 8	1		ENSP00000354764.4
KCNN3	ENST00000358505.2	c.946G>A	p.Val316Met	missense_variant	Exon 7 of 8	1		ENSP00000351295.2
KCNN3	ENST00000618040.4	c.1930G>A	p.Val644Met	missense_variant	Exon 8 of 9	5		ENSP00000481848.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Jan 05, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.83
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Benign	0.32	.;T;.;.
Eigen	Pathogenic	0.71
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.96	D;D;D;D
M_CAP	Pathogenic	0.45	D
MetaRNN	Uncertain	0.68	D;D;D;D
MetaSVM	Pathogenic	1.1	D
PrimateAI	Pathogenic	0.86	D
PROVEAN	Benign	-2.2	N;.;N;N
REVEL	Pathogenic	0.83
Sift	Uncertain	0.0060	D;.;D;D
Sift4G	Uncertain	0.027	D;D;D;D
Polyphen		0.72	.;.;P;.
Vest4		0.66
MVP		0.89
MPC		1.3
ClinPred		0.97	D
GERP RS		5.0
Varity_R		0.31
gMVP		0.78

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: rs1557937420; hg19: chr1-154685954; COSMIC: COSV55220194;