1-154772052-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_002249.6(KCNN3):c.1371C>G(p.Ile457Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: KCNN3 NM_002249.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.84

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
• PP2: Missense variant where missense usually causes diseases, KCNN3
• BP4: Computational evidence support a benign effect (MetaRNN=0.3730674).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNN3	NM_002249.6	c.1371C>G	p.Ile457Met	missense_variant	3/8	ENST00000271915.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNN3	ENST00000271915.9	c.1371C>G	p.Ile457Met	missense_variant	3/8	1	NM_002249.6	P1
KCNN3	ENST00000361147.8	c.456C>G	p.Ile152Met	missense_variant	3/8	1
KCNN3	ENST00000358505.2	c.432C>G	p.Ile144Met	missense_variant	3/8	1
KCNN3	ENST00000618040.4	c.1371C>G	p.Ile457Met	missense_variant	3/9	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Mar 21, 2023

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on 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	0.66
BayesDel_addAF	Uncertain	0.034	T
BayesDel_noAF	Benign	-0.19
Cadd	Uncertain	25
Dann	Uncertain	1.0
Eigen	Uncertain	0.49
Eigen_PC	Uncertain	0.48
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.94	D;D;D;D
M_CAP	Benign	0.0076	T
MetaRNN	Benign	0.37	T;T;T;T
MetaSVM	Benign	-1.0	T
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.84	D
PROVEAN	Uncertain	-2.4	N;.;D;D
REVEL	Benign	0.17
Sift	Benign	0.060	T;.;T;T
Sift4G	Uncertain	0.038	D;D;T;T
Polyphen		0.34	.;.;B;.
Vest4		0.46
MVP		0.37
MPC		1.6
ClinPred		0.94	D
GERP RS		4.7
Varity_R		0.45
gMVP		0.91

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: rs1648583329; hg19: chr1-154744528;