rs78672251

Positions:

• chr10-76944973-A-G

Variant summary

Our verdict is Benign. Variant got -18 ACMG points: 0P and 18B. BP4_Moderate BP6_Very_Strong BA1

The NM_001161352.2(KCNMA1):​c.2710-8T>C variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00586 in 1,612,758 control chromosomes in the GnomAD database, including 446 homozygotes. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Benign (★★).

• Frequency:
  • Genomes: 𝑓 0.030 (214 hom., cov: 32)
  • Exomes 𝑓: 0.0034 (232 hom.)
• Consequence: KCNMA1 NM_001161352.2 splice_region, splice_polypyrimidine_tract, intron
• Scores: Splicing: ADA: 0.008184
• Clinical Significance: Benign criteria provided, multiple submitters, no conflicts B:5
• Conservation: PhyloP100: 2.82

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-AS1 (HGNC:51213): (KCNMA1 antisense RNA 1)

LOC124902466 (HGNC:):

ACMG classification

Verdict is Benign. Variant got -18 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.36).
• BP6: Variant 10-76944973-A-G is Benign according to our data. Variant chr10-76944973-A-G is described in ClinVar as [Benign]. Clinvar id is 129325.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr10-76944973-A-G is described in Lovd as [Likely_benign].
• BA1: GnomAd4 highest subpopulation (AFR) allele frequency at 95% confidence interval = 0.0991 is higher than 0.05.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNMA1	NM_001161352.2	c.2710-8T>C		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000286628.14	NP_001154824.1
KCNMA1-AS1	NR_120655.1	n.458-32637A>G		intron_variant, non_coding_transcript_variant
LOC124902466	XR_007062207.1	n.381-3993A>G		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNMA1	ENST00000286628.14	c.2710-8T>C		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		1	NM_001161352.2	ENSP00000286628	A2
KCNMA1-AS1	ENST00000458661.6	n.426-32637A>G		intron_variant, non_coding_transcript_variant		3

Frequencies

GnomAD3 genomes AF: 0.0297 AC: 4508 AN: 151840 Hom.: 212 Cov.: 32

Gnomad AFR AF: 0.102

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0153

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000416

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.0127

Gnomad NFE AF: 0.000515

Gnomad OTH AF: 0.0216

GnomAD3 exomes AF: 0.00806 AC: 2024 AN: 251252 Hom.: 81 AF XY: 0.00605 AC XY: 822 AN XY: 135820

Gnomad AFR exome AF: 0.105

Gnomad AMR exome AF: 0.00619

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.000229

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000555

Gnomad OTH exome AF: 0.00506

GnomAD4 exome AF: 0.00338 AC: 4937 AN: 1460800 Hom.: 232 Cov.: 32 AF XY: 0.00294 AC XY: 2136 AN XY: 726806

Gnomad4 AFR exome AF: 0.110

Gnomad4 AMR exome AF: 0.00653

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.000267

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000455

Gnomad4 OTH exome AF: 0.00687

GnomAD4 genome AF: 0.0298 AC: 4521 AN: 151958 Hom.: 214 Cov.: 32 AF XY: 0.0292 AC XY: 2169 AN XY: 74300

Gnomad4 AFR AF: 0.102

Gnomad4 AMR AF: 0.0153

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000416

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000515

Gnomad4 OTH AF: 0.0214

Alfa AF: 0.0188 Hom.: 62

Bravo AF: 0.0344

Asia WGS AF: 0.00693 AC: 24 AN: 3478

ClinVar

Significance: Benign

Submissions summary: Benign:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Benign:2

Benign, criteria provided, single submitter	clinical testing	GeneDx	Jul 21, 2018	- -
Benign, criteria provided, single submitter	not provided	Breakthrough Genomics, Breakthrough Genomics	-	- -

Generalized epilepsy-paroxysmal dyskinesia syndrome Benign:2

Benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 12, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -
Benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Feb 01, 2024	- -

not specified Benign:1

Likely benign, no assertion criteria provided

clinical testing

Genetic Services Laboratory, University of Chicago

-

Likely benign based on allele frequency in 1000 Genomes Project or ESP global frequency and its presence in a patient with a rare or unrelated disease phenotype. NOT Sanger confirmed. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.36
CADD	Benign	14
DANN	Benign	0.90

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.0082
dbscSNV1_RF	Benign	0.10
SpliceAI score (max)		0.020		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: rs78672251; hg19: chr10-78704731;