10-76949303-C-T

Variant summary

Our verdict is Benign. Variant got -19 ACMG points: 1P and 20B. PP2 BP4_Strong BP6_Very_Strong BS1 BS2

The NM_001161352.2(KCNMA1):c.2548G>A(p.Val850Ile) variant causes a missense change. The variant allele was found at a frequency of 0.000324 in 1,614,042 control chromosomes in the GnomAD database, including 5 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. V850V) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.00028 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00033 (5 hom.)
• Consequence: KCNMA1 NM_001161352.2 missense
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:6
• Conservation: PhyloP100: 5.02

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]

LOC124902466 (HGNC:):

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

ACMG classification

Verdict is Benign. Variant got -19 ACMG points.

• PP2: Missense variant where missense usually causes diseases, KCNMA1
• BP4: Computational evidence support a benign effect (MetaRNN=0.008610874).
• BP6: Variant 10-76949303-C-T is Benign according to our data. Variant chr10-76949303-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 464295.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BS1: Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.000276 (42/152178) while in subpopulation SAS AF= 0.0027 (13/4820). AF 95% confidence interval is 0.00159. There are 0 homozygotes in gnomad4. There are 24 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
• BS2: High Homozygotes in GnomAdExome at 3 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNMA1	NM_001161352.2	c.2548G>A	p.Val850Ile	missense_variant	22/28	ENST00000286628.14
LOC124902466	XR_007062207.1	n.718C>T		non_coding_transcript_exon_variant	3/3
KCNMA1-AS1	NR_120655.1	n.458-28307C>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNMA1	ENST00000286628.14	c.2548G>A	p.Val850Ile	missense_variant	22/28	1	NM_001161352.2	A2
KCNMA1-AS1	ENST00000458661.6	n.426-28307C>T		intron_variant, non_coding_transcript_variant		3

Frequencies

GnomAD3 genomes AF: 0.000283 AC: 43 AN: 152060 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00290

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000397

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000577 AC: 145 AN: 251132 Hom.: 3 AF XY: 0.000855 AC XY: 116 AN XY: 135748

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00337

Gnomad FIN exome AF: 0.0000462

Gnomad NFE exome AF: 0.000335

Gnomad OTH exome AF: 0.000326

GnomAD4 exome AF: 0.000329 AC: 481 AN: 1461864 Hom.: 5 Cov.: 31 AF XY: 0.000470 AC XY: 342 AN XY: 727232

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.0000447

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000756

Gnomad4 SAS exome AF: 0.00321

Gnomad4 FIN exome AF: 0.0000374

Gnomad4 NFE exome AF: 0.000140

Gnomad4 OTH exome AF: 0.000513

GnomAD4 genome AF: 0.000276 AC: 42 AN: 152178 Hom.: 0 Cov.: 32 AF XY: 0.000323 AC XY: 24 AN XY: 74390

Gnomad4 AFR AF: 0.0000482

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00270

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000397

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000263 Hom.: 0

Bravo AF: 0.000185

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.000259 AC: 1

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000233 AC: 2

ExAC AF: 0.000708 AC: 86

Asia WGS AF: 0.000577 AC: 2 AN: 3478

EpiCase AF: 0.000763

EpiControl AF: 0.000652

ClinVar

Significance: Likely benign

Submissions summary: Benign:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Benign:2

Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Mar 01, 2024	KCNMA1: PP2, BS2 -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jun 19, 2020	- -

Generalized epilepsy-paroxysmal dyskinesia syndrome Benign:2

Likely 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 likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -
Likely benign, criteria provided, single submitter	clinical testing	Invitae	Jan 11, 2024	- -

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

Jan 25, 2018

- -

KCNMA1-related disorder Benign:1

Likely benign, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Jun 02, 2022

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
AlphaMissense	Benign	0.075
BayesDel_addAF	Benign	-0.41	T
BayesDel_noAF	Benign	-0.37
Cadd	Uncertain	24
Dann	Uncertain	1.0
DEOGEN2	Benign	0.016	T;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;T;.;.;.;.;.;.;.;.;.;.;.;.;.
Eigen	Benign	-0.021
Eigen_PC	Benign	0.21
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.93	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;.;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Benign	0.0046	T
MetaRNN	Benign	0.0086	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;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
PrimateAI	Uncertain	0.72	T
Sift4G	Benign	0.13	T;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;T;T;T;.;.;.;.;.;.;.;.;T;.;.;.
Polyphen		0.24, 0.095, 0.12, 0.0050	.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;B;B;B;.;.;.;.;.;.;B;B;.;.;B;.;.;.
Vest4		0.39, 0.39, 0.43, 0.41, 0.37, 0.40
MVP		0.56
MPC		1.0
ClinPred		0.036	T
GERP RS		5.6
Varity_R		0.34
gMVP		0.36

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

LitVar

Other links and lift over

dbSNP: rs142770262; hg19: chr10-78709061;