rs13377017

Variant names:

• chr10-76953794-C-T
• rs13377017
• NM_001161352.2:c.2484+7G>A

Variant summary

Our verdict is Benign. Variant got -14 ACMG points: 0P and 14B. BP4_Moderate BP6_Very_Strong BS1

The NM_001161352.2(KCNMA1):​c.2484+7G>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000288 in 1,614,000 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.0016 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00015 (0 hom.)
• Consequence: KCNMA1 NM_001161352.2 splice_region, intron
• Scores: Splicing: ADA: 0.00003817
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:5
• Conservation: PhyloP100: 1.25

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)

ACMG classification

Verdict is Benign. Variant got -14 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.43).
• BP6: Variant 10-76953794-C-T is Benign according to our data. Variant chr10-76953794-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 532948.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00163 (249/152300) while in subpopulation AFR AF= 0.00585 (243/41558). AF 95% confidence interval is 0.00524. There are 0 homozygotes in gnomad4. There are 106 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNMA1	NM_001161352.2	c.2484+7G>A		splice_region_variant, intron_variant	Intron 21 of 27	ENST00000286628.14	NP_001154824.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNMA1	ENST00000286628.14	c.2484+7G>A		splice_region_variant, intron_variant	Intron 21 of 27	1	NM_001161352.2	ENSP00000286628.8

Frequencies

GnomAD3 genomes AF: 0.00164 AC: 249 AN: 152182 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00586

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000262

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.000479

GnomAD3 exomes AF: 0.000350 AC: 88 AN: 251302 Hom.: 0 AF XY: 0.000228 AC XY: 31 AN XY: 135818

Gnomad AFR exome AF: 0.00511

Gnomad AMR exome AF: 0.000116

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000148 AC: 216 AN: 1461700 Hom.: 0 Cov.: 32 AF XY: 0.000129 AC XY: 94 AN XY: 727154

Gnomad4 AFR exome AF: 0.00568

Gnomad4 AMR exome AF: 0.000157

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.000248

GnomAD4 genome AF: 0.00163 AC: 249 AN: 152300 Hom.: 0 Cov.: 32 AF XY: 0.00142 AC XY: 106 AN XY: 74480

Gnomad4 AFR AF: 0.00585

Gnomad4 AMR AF: 0.000261

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.000474

Alfa AF: 0.000552 Hom.: 0

Bravo AF: 0.00178

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:2

Jun 20, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: KCNMA1 c.2484+7G>A alters a conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Consensus agreement among computation tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.00035 in 251302 control chromosomes, predominantly at a frequency of 0.0051 within the African or African-American subpopulation in the gnomAD database, suggesting the variant may be benign. To our knowledge, no occurrence of c.2484+7G>A in individuals affected with Paroxysmal Nonkinesigenic Dyskinesia, 3, With Or Without Generalized Epilepsy and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 532948). Based on the evidence outlined above, the variant was classified as likely benign. -

Oct 30, 2017

Eurofins Ntd Llc (ga)

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Generalized epilepsy-paroxysmal dyskinesia syndrome Benign:1

Jan 30, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cerebellar atrophy, developmental delay, and seizures;C5231421:Epilepsy, idiopathic generalized, susceptibility to, 16;C5231479:Liang-Wang syndrome;C5574945:Generalized epilepsy-paroxysmal dyskinesia syndrome Benign:1

May 26, 2022

Center for Genomics, Ann and Robert H. Lurie Children's Hospital of Chicago

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature but is present in the Genome Aggregation Database (Highest reported MAF 0.5% (243/41436) (https://gnomad.broadinstitute.org/variant/10-76953794-C-T?dataset=gnomad_r3). This variant is present in ClinVar, with several labs classifying this variant as Benign (Variation ID:532948). Evolutionary conservation and computational predictive tools for this variant are limited or unavailable. This variant is an intronic variant with no predicted change in the amino acid sequence but may have an unknown effect on splicing. Splice prediction tools suggest that this variant may not affect splicing. Further studies are needed to understand its impact. In summary, data on this variant suggests that this variant does not cause disease but requires further evidence. Therefore, this variant is classified as likely benign. -

KCNMA1-related disorder Benign:1

Oct 25, 2022

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.43
CADD	Benign	6.8
DANN	Benign	0.62

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000038
dbscSNV1_RF	Benign	0.016
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: rs13377017; hg19: chr10-78713552;