10-76884988-C-T

Variant names:

• chr10-76884988-C-T
• rs886047257
• NM_001161352.2:c.*2278G>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_001161352.2(KCNMA1):​c.*2278G>A variant causes a 3 prime UTR change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000129 in 1,547,720 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
  • Exomes 𝑓: 7.2e-7 (0 hom.)
• Consequence: KCNMA1 NM_001161352.2 3_prime_UTR
• Scores: Splicing: ADA: 0.9945
• 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: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P, ClinGen, Orphanet, Illumina
• Liang-Wang syndrome

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

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNMA1	NM_001161352.2	MANE Select	c.*2278G>A		3_prime_UTR	Exon 28 of 28	NP_001154824.1	Q12791-1
	KCNMA1	NM_001437422.1		c.*2278G>A		3_prime_UTR	Exon 28 of 28	NP_001424351.1
	KCNMA1	NM_001161353.2		c.*2278G>A		3_prime_UTR	Exon 28 of 28	NP_001154825.1	Q12791-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNMA1	ENST00000286628.14	TSL:1 MANE Select	c.*2278G>A		3_prime_UTR	Exon 28 of 28	ENSP00000286628.8	Q12791-1
	KCNMA1	ENST00000286627.10	TSL:1	c.*2278G>A		3_prime_UTR	Exon 27 of 27	ENSP00000286627.5	Q12791-5
	KCNMA1	ENST00000640807.1	TSL:1	c.3362+2303G>A		intron	N/A	ENSP00000491555.1	D5MRH1

Frequencies

GnomAD3 genomes AF: 0.00000659 AC: 1 AN: 151734 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.000288

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 7.16e-7 AC: 1 AN: 1395986 Hom.: 0 Cov.: 30 AF XY: 0.00000145 AC XY: 1 AN XY: 688472

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 31470

American (AMR) AF: 0.00 AC: 0 AN: 35404

Ashkenazi Jewish (ASJ) AF: 0.0000398 AC: 1 AN: 25144

East Asian (EAS) AF: 0.00 AC: 0 AN: 35536

South Asian (SAS) AF: 0.00 AC: 0 AN: 78724

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 48354

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5690

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1077638

Other (OTH) AF: 0.00 AC: 0 AN: 58026

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.00000659 AC: 1 AN: 151734 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 74072

African (AFR) AF: 0.00 AC: 0 AN: 41330

American (AMR) AF: 0.00 AC: 0 AN: 15230

Ashkenazi Jewish (ASJ) AF: 0.000288 AC: 1 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5178

South Asian (SAS) AF: 0.00 AC: 0 AN: 4808

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67978

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Generalized epilepsy-paroxysmal dyskinesia syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.18
BayesDel_addAF	Uncertain	0.066	T
BayesDel_noAF	Benign	-0.14
CADD	Uncertain	24
DANN	Uncertain	0.99
Eigen	Uncertain	0.52
Eigen_PC	Uncertain	0.63
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		7.6
GERP RS		6.1
Mutation Taster		=0/100	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.99
dbscSNV1_RF	Pathogenic	0.92
SpliceAI score (max)		0.010		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: rs886047257; hg19: chr10-78644746;