rs77602559

Variant summary

Our verdict is Benign. The variant received -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_001161352.2(KCNMA1):​c.34A>G​(p.Ser12Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0022 in 1,520,716 control chromosomes in the GnomAD database, including 9 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0057 ( 5 hom., cov: 32)
Exomes 𝑓: 0.0018 ( 4 hom. )

Consequence

KCNMA1
NM_001161352.2 missense

Scores

2
1
15

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts U:1B:9

Conservation

PhyloP100: 0.101

Publications

6 publications found
Variant links:
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)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -20 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.0055193007).
BP6
Variant 10-77637609-T-C is Benign according to our data. Variant chr10-77637609-T-C is described in ClinVar as [Likely_benign]. Clinvar id is 193223.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 = 0.0057 (851/149174) while in subpopulation AFR AF = 0.0147 (597/40538). AF 95% confidence interval is 0.0137. There are 5 homozygotes in GnomAd4. There are 393 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
BS2
High Homozygotes in GnomAd4 at 5 AR,AD gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNMA1NM_001161352.2 linkc.34A>G p.Ser12Gly missense_variant Exon 1 of 28 ENST00000286628.14 NP_001154824.1 Q12791-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNMA1ENST00000286628.14 linkc.34A>G p.Ser12Gly missense_variant Exon 1 of 28 1 NM_001161352.2 ENSP00000286628.8 Q12791-1

Frequencies

GnomAD3 genomes
AF:
0.00570
AC:
850
AN:
149072
Hom.:
5
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0147
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00532
Gnomad ASJ
AF:
0.00146
Gnomad EAS
AF:
0.00242
Gnomad SAS
AF:
0.000866
Gnomad FIN
AF:
0.00116
Gnomad MID
AF:
0.00671
Gnomad NFE
AF:
0.00194
Gnomad OTH
AF:
0.00491
GnomAD2 exomes
AF:
0.00204
AC:
255
AN:
125036
AF XY:
0.00200
show subpopulations
Gnomad AFR exome
AF:
0.0106
Gnomad AMR exome
AF:
0.00322
Gnomad ASJ exome
AF:
0.00118
Gnomad EAS exome
AF:
0.00140
Gnomad FIN exome
AF:
0.00131
Gnomad NFE exome
AF:
0.00125
Gnomad OTH exome
AF:
0.00338
GnomAD4 exome
AF:
0.00182
AC:
2496
AN:
1371542
Hom.:
4
Cov.:
33
AF XY:
0.00178
AC XY:
1201
AN XY:
676296
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.0130
AC:
399
AN:
30732
American (AMR)
AF:
0.00379
AC:
131
AN:
34548
Ashkenazi Jewish (ASJ)
AF:
0.00163
AC:
40
AN:
24556
East Asian (EAS)
AF:
0.00187
AC:
66
AN:
35206
South Asian (SAS)
AF:
0.000860
AC:
67
AN:
77920
European-Finnish (FIN)
AF:
0.00167
AC:
59
AN:
35334
Middle Eastern (MID)
AF:
0.00441
AC:
22
AN:
4992
European-Non Finnish (NFE)
AF:
0.00145
AC:
1550
AN:
1071072
Other (OTH)
AF:
0.00283
AC:
162
AN:
57182
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.360
Heterozygous variant carriers
0
107
214
322
429
536
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
58
116
174
232
290
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00570
AC:
851
AN:
149174
Hom.:
5
Cov.:
32
AF XY:
0.00539
AC XY:
393
AN XY:
72928
show subpopulations
African (AFR)
AF:
0.0147
AC:
597
AN:
40538
American (AMR)
AF:
0.00531
AC:
80
AN:
15054
Ashkenazi Jewish (ASJ)
AF:
0.00146
AC:
5
AN:
3418
East Asian (EAS)
AF:
0.00243
AC:
12
AN:
4936
South Asian (SAS)
AF:
0.000867
AC:
4
AN:
4612
European-Finnish (FIN)
AF:
0.00116
AC:
12
AN:
10372
Middle Eastern (MID)
AF:
0.00725
AC:
2
AN:
276
European-Non Finnish (NFE)
AF:
0.00193
AC:
129
AN:
67010
Other (OTH)
AF:
0.00485
AC:
10
AN:
2060
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.446
Heterozygous variant carriers
0
43
86
129
172
215
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
20
40
60
80
100
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00589
Hom.:
0
Bravo
AF:
0.00637
ExAC
AF:
0.000243
AC:
12

ClinVar

Significance: Benign/Likely benign
Submissions summary: Uncertain:1Benign:9
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:3
Jun 06, 2019
Genetic Services Laboratory, University of Chicago
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jul 05, 2024
Athena Diagnostics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 18, 2015
Eurofins Ntd Llc (ga)
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Benign:3
-
Breakthrough Genomics, Breakthrough Genomics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

Aug 07, 2018
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is associated with the following publications: (PMID: 19266219) -

May 01, 2025
CeGaT Center for Human Genetics Tuebingen
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

KCNMA1: BS1, BS2 -

Generalized epilepsy-paroxysmal dyskinesia syndrome Benign:2
Feb 02, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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 likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Intellectual disability Uncertain:1
Jan 01, 2019
Centre de Biologie Pathologie Génétique, Centre Hospitalier Universitaire de Lille
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

KCNMA1-related disorder Benign:1
Nov 29, 2021
PreventionGenetics, part of Exact Sciences
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as 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
AlphaMissense
Benign
0.053
BayesDel_addAF
Uncertain
0.019
T
BayesDel_noAF
Benign
-0.21
CADD
Benign
15
DANN
Benign
0.76
DEOGEN2
Benign
0.0053
.;.;.;.;.;.;.;.;.;.;.;T;.;T;.;.;.;.;.;.;.;.;.;.;T;.;.;.;.;.;.;.;.;.;.;.;.
Eigen
Benign
-0.74
Eigen_PC
Benign
-0.65
FATHMM_MKL
Benign
0.12
N
LIST_S2
Benign
0.80
T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;.;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaRNN
Benign
0.0055
T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM
Benign
-0.89
T
MutationAssessor
Benign
0.0
.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;N;N;N;.;N;.;.;N;N;N;.;.;N;.;.
PhyloP100
0.10
PrimateAI
Pathogenic
0.87
D
PROVEAN
Benign
0.050
.;.;.;.;.;N;.;.;.;.;.;.;.;N;.;.;.;.;.;.;.;.;.;N;.;.;.;.;.;.;.;.;.;.;.;.;.
REVEL
Benign
0.27
Sift
Pathogenic
0.0
.;.;.;.;.;D;.;.;.;.;.;.;.;D;.;.;.;.;.;.;.;.;.;D;.;.;.;.;.;.;.;.;.;.;.;.;.
Sift4G
Benign
0.49
.;.;.;.;.;T;.;.;.;.;.;T;.;T;.;.;.;.;.;.;.;.;.;T;T;.;.;.;.;T;.;.;.;.;T;T;T
Polyphen
0.0
.;.;.;.;.;B;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;B;.;B;B;.;.;B;.;B;.;.;.;.;B;.;.
Vest4
0.21, 0.23, 0.20, 0.17, 0.22, 0.21, 0.28, 0.20, 0.23
MVP
0.65
ClinPred
0.079
T
GERP RS
-1.6
PromoterAI
-0.0050
Neutral
Varity_R
0.066
gMVP
0.32
Mutation Taster
=98/2
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

Publications

Other links and lift over

dbSNP: rs77602559; hg19: chr10-79397367; API