NM_001161352.2:c.3653G>T

Variant names:

• chr10-76887324-C-A
• rs200723995
• NM_001161352.2:c.3653G>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_001161352.2(KCNMA1):​c.3653G>T​(p.Arg1218Leu) 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1218Q) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: KCNMA1 NM_001161352.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.57
• Publications: 0 publications found

Genes affected

KCNMA1 (HGNC:6284): (potassium calcium-activated channel subfamily M alpha 1) This gene encodes the alpha subunit of calcium-activated BK channel. The encoded protein is involved in several physiological processes including smooth muscle contraction, neurotransmitter release and neuronal excitability. Mutations in this gene are associated with a spectrum of neurological disorders including Paroxysmal Nonkinesigenic Dyskinesia 3, Idiopathic Generalized Epilepsy 16 and Liang-Wang syndrome. [provided by RefSeq, Aug 2022]

KCNMA1 Gene-Disease associations (from GenCC):

• generalized epilepsy-paroxysmal dyskinesia syndrome

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Illumina, G2P, Ambry Genetics, Orphanet, Labcorp Genetics (formerly Invitae), ClinGen
• Liang-Wang syndrome

  Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics
• cerebellar atrophy, developmental delay, and seizures

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 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
KCNMA1	NM_001161352.2	c.3653G>T	p.Arg1218Leu	missense_variant	Exon 28 of 28	ENST00000286628.14	NP_001154824.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNMA1	ENST00000286628.14	c.3653G>T	p.Arg1218Leu	missense_variant	Exon 28 of 28	1	NM_001161352.2	ENSP00000286628.8

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Jun 07, 2022

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	Uncertain	0.49
BayesDel_addAF	Pathogenic	0.31	D
BayesDel_noAF	Pathogenic	0.20
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.021	T;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;T;.;.;.;.;.;.;.;.;.;.;.;.
Eigen	Uncertain	0.27
Eigen_PC	Uncertain	0.41
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;.;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.29	D
MetaRNN	Uncertain	0.56	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.30	D
MutationAssessor	Benign	0.0	.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;N;.;.;.;.;.;.;.;.;.;.;.;.;.
PhyloP100		7.6
PrimateAI	Uncertain	0.77	T
PROVEAN	Benign	-1.4	.;.;.;.;.;.;.;.;N;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;D;.;.;.;.;N;.;.;.;.;.;.;.;.;.;.;.;.;.;.
REVEL	Uncertain	0.51
Sift	Uncertain	0.0020	.;.;.;.;.;.;.;.;D;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;D;.;.;.;.;D;.;.;.;.;.;.;.;.;.;.;.;.;.;.
Sift4G	Benign	0.87	T;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;D;D;T;T;.;.;.;.;.;.;.;.;D;.;.
Polyphen		0.68, 1.0, 0.70, 0.80	.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;P;D;P;.;.;.;.;.;.;P;P;.;.;P;.;.
Vest4		0.70, 0.61, 0.73, 0.62, 0.38, 0.77
MutPred		0.17		.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;Loss of MoRF binding (P = 0.0739);Loss of MoRF binding (P = 0.0739);.;.;.;.;.;.;.;.;.;.;.;.;.;.;Loss of MoRF binding (P = 0.0739);.;.;.;Loss of MoRF binding (P = 0.0739);.;.;.;.;.;.;.;.;.;.;.;.;.;
MVP		0.85
MPC		0.63
ClinPred		0.93	D
GERP RS		5.2
Varity_R		0.40
gMVP		0.67
Mutation Taster		=53/47	polymorphism

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

Other links and lift over

dbSNP: rs200723995; hg19: chr10-78647082;