NM_001161352.2:c.3653G>C

Variant names:

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

Variant summary

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

The NM_001161352.2(KCNMA1):​c.3653G>C​(p.Arg1218Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,884 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. 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)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: KCNMA1 NM_001161352.2 missense
• Clinical Significance: Not reported in ClinVar
• 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

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001161352.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNMA1	NM_001161352.2	MANE Select	c.3653G>C	p.Arg1218Pro	missense	Exon 28 of 28	NP_001154824.1
	KCNMA1	NM_001437422.1		c.3611G>C	p.Arg1204Pro	missense	Exon 28 of 28	NP_001424351.1
	KCNMA1	NM_001161353.2		c.3602G>C	p.Arg1201Pro	missense	Exon 28 of 28	NP_001154825.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNMA1	ENST00000286628.14	TSL:1 MANE Select	c.3653G>C	p.Arg1218Pro	missense	Exon 28 of 28	ENSP00000286628.8
	KCNMA1	ENST00000626620.3	TSL:1	c.3602G>C	p.Arg1201Pro	missense	Exon 28 of 28	ENSP00000485867.1
	KCNMA1	ENST00000639406.1	TSL:1	c.3569G>C	p.Arg1190Pro	missense	Exon 29 of 29	ENSP00000491732.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461884 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727246

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112004

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.62
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.26
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.020	T
Eigen	Uncertain	0.40
Eigen_PC	Uncertain	0.50
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Pathogenic	0.39	D
MetaRNN	Uncertain	0.64	D
MetaSVM	Uncertain	0.42	D
MutationAssessor	Benign	0.0	N
PhyloP100		7.6
PrimateAI	Uncertain	0.78	T
PROVEAN	Benign	-1.0	N
REVEL	Uncertain	0.57
Sift	Uncertain	0.0030	D
Sift4G	Benign	0.26	T
Polyphen		0.94	P
Vest4		0.68
MutPred		0.27		Gain of glycosylation at R1218 (P = 0.0069)
MVP		0.85
MPC		0.92
ClinPred		0.93	D
GERP RS		5.2
Varity_R		0.47
gMVP		0.70
Mutation Taster		=50/50

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;