10-77637586-TCCGCCGCCGCCGCCG-TCCGCCGCCGCCGCCGCCG

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP3BP6BS1

The NM_001161352.2(KCNMA1):​c.54_56dupCGG​(p.Gly19dup) variant causes a disruptive inframe insertion change. The variant allele was found at a frequency of 0.000563 in 1,524,852 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00087 ( 1 hom., cov: 32)
Exomes 𝑓: 0.00053 ( 0 hom. )

Consequence

KCNMA1
NM_001161352.2 disruptive_inframe_insertion

Scores

Not classified

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:4O:1

Conservation

PhyloP100: 5.59

Publications

0 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: Likely_benign. The variant received -6 ACMG points.

BP3
Nonframeshift variant in repetitive region in NM_001161352.2
BP6
Variant 10-77637586-T-TCCG is Benign according to our data. Variant chr10-77637586-T-TCCG is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 193225.
BS1
Variant frequency is greater than expected in population amr. GnomAd4 allele frequency = 0.000873 (132/151214) while in subpopulation AMR AF = 0.00203 (31/15238). AF 95% confidence interval is 0.00147. There are 1 homozygotes in GnomAd4. There are 51 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNMA1NM_001161352.2 linkc.54_56dupCGG p.Gly19dup disruptive_inframe_insertion 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.54_56dupCGG p.Gly19dup disruptive_inframe_insertion Exon 1 of 28 1 NM_001161352.2 ENSP00000286628.8 Q12791-1

Frequencies

GnomAD3 genomes
AF:
0.000867
AC:
131
AN:
151110
Hom.:
1
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000948
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00204
Gnomad ASJ
AF:
0.00203
Gnomad EAS
AF:
0.000197
Gnomad SAS
AF:
0.000209
Gnomad FIN
AF:
0.000190
Gnomad MID
AF:
0.00327
Gnomad NFE
AF:
0.000724
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000655
AC:
75
AN:
114424
AF XY:
0.000604
show subpopulations
Gnomad AFR exome
AF:
0.00145
Gnomad AMR exome
AF:
0.00100
Gnomad ASJ exome
AF:
0.00167
Gnomad EAS exome
AF:
0.000817
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000479
Gnomad OTH exome
AF:
0.00175
GnomAD4 exome
AF:
0.000529
AC:
726
AN:
1373638
Hom.:
0
Cov.:
31
AF XY:
0.000511
AC XY:
346
AN XY:
677458
show subpopulations
African (AFR)
AF:
0.00100
AC:
31
AN:
30918
American (AMR)
AF:
0.000980
AC:
34
AN:
34686
Ashkenazi Jewish (ASJ)
AF:
0.00198
AC:
49
AN:
24704
East Asian (EAS)
AF:
0.000710
AC:
25
AN:
35200
South Asian (SAS)
AF:
0.000410
AC:
32
AN:
77966
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
36758
Middle Eastern (MID)
AF:
0.000200
AC:
1
AN:
5006
European-Non Finnish (NFE)
AF:
0.000467
AC:
500
AN:
1071120
Other (OTH)
AF:
0.000943
AC:
54
AN:
57280
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.440
Heterozygous variant carriers
0
37
73
110
146
183
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
22
44
66
88
110
<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:
0.000873
AC:
132
AN:
151214
Hom.:
1
Cov.:
32
AF XY:
0.000690
AC XY:
51
AN XY:
73878
show subpopulations
African (AFR)
AF:
0.000946
AC:
39
AN:
41238
American (AMR)
AF:
0.00203
AC:
31
AN:
15238
Ashkenazi Jewish (ASJ)
AF:
0.00203
AC:
7
AN:
3454
East Asian (EAS)
AF:
0.000198
AC:
1
AN:
5054
South Asian (SAS)
AF:
0.000210
AC:
1
AN:
4770
European-Finnish (FIN)
AF:
0.000190
AC:
2
AN:
10516
Middle Eastern (MID)
AF:
0.00352
AC:
1
AN:
284
European-Non Finnish (NFE)
AF:
0.000724
AC:
49
AN:
67648
Other (OTH)
AF:
0.000475
AC:
1
AN:
2106
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.504
Heterozygous variant carriers
0
6
12
18
24
30
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.000364
Hom.:
0

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:3Benign:4Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not specified Uncertain:1Benign:1
Apr 28, 2017
Athena Diagnostics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Apr 05, 2016
Eurofins Ntd Llc (ga)
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1Benign:1
Jul 25, 2025
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In-frame duplication of 1 amino acid in a repetitive region with no known function; Has not been previously published as pathogenic or benign to our knowledge -

Dec 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

KCNMA1: BP3, BS2 -

Generalized epilepsy-paroxysmal dyskinesia syndrome Uncertain:1
Dec 30, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant, c.54_56dup, results in the insertion of 1 amino acid(s) of the KCNMA1 protein (p.Gly20dup), but otherwise preserves the integrity of the reading frame. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with KCNMA1-related conditions. ClinVar contains an entry for this variant (Variation ID: 193225). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Inborn genetic diseases Benign:1
Mar 31, 2021
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

KCNMA1-related disorder Benign:1
Sep 08, 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). -

Infantile epileptic dyskinetic encephalopathy;C5574945:Generalized epilepsy-paroxysmal dyskinesia syndrome Other:1
-
GenomeConnect - Invitae Patient Insights Network
Significance:not provided
Review Status:no classification provided
Collection Method:phenotyping only

Variant interpreted as Uncertain significance and reported on 09-24-2018 by Invitae. GenomeConnect-Invitae Patient Insights Network assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. Registry team members make no attempt to reinterpret the clinical significance of the variant. Phenotypic details are available under supporting information. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
5.6
Mutation Taster
=77/23
polymorphism

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs760628050; hg19: chr10-79397344; API