10-76885501-A-G

Variant summary

Our verdict is Benign. Variant got -12 ACMG points: 0P and 12B. BP4_Moderate BP6_Moderate BS1 BS2

The NM_001161352.2(KCNMA1):c.*1765T>C variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00116 in 985,290 control chromosomes in the GnomAD database, including 8 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.0050 (6 hom., cov: 31)
  • Exomes 𝑓: 0.00046 (2 hom.)
• Consequence: KCNMA1 NM_001161352.2 3_prime_UTR
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 0.669

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]

ACMG classification

Verdict is Benign. Variant got -12 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.31).
• BP6: Variant 10-76885501-A-G is Benign according to our data. Variant chr10-76885501-A-G is described in ClinVar as [Likely_benign]. Clinvar id is 300931.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00501 (762/152178) while in subpopulation AFR AF= 0.0172 (715/41494). AF 95% confidence interval is 0.0162. There are 6 homozygotes in gnomad4. There are 350 alleles in male gnomad4 subpopulation. Median coverage is 31. This position pass quality control queck.
• BS2: High Homozygotes in GnomAd at 7 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNMA1	NM_001161352.2	c.*1765T>C		3_prime_UTR_variant	28/28	ENST00000286628.14

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNMA1	ENST00000286628.14	c.*1765T>C		3_prime_UTR_variant	28/28	1	NM_001161352.2	A2

Frequencies

GnomAD3 genomes AF: 0.00501 AC: 762 AN: 152062 Hom.: 7 Cov.: 31

Gnomad AFR AF: 0.0173

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00151

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00949

Gnomad NFE AF: 0.000132

Gnomad OTH AF: 0.00574

GnomAD4 exome AF: 0.000460 AC: 383 AN: 833112 Hom.: 2 Cov.: 30 AF XY: 0.000395 AC XY: 152 AN XY: 384716

Gnomad4 AFR exome AF: 0.0206

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000407

Gnomad4 OTH exome AF: 0.000769

GnomAD4 genome AF: 0.00501 AC: 762 AN: 152178 Hom.: 6 Cov.: 31 AF XY: 0.00470 AC XY: 350 AN XY: 74412

Gnomad4 AFR AF: 0.0172

Gnomad4 AMR AF: 0.00151

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000132

Gnomad4 OTH AF: 0.00568

Alfa AF: 0.00364 Hom.: 0

Bravo AF: 0.00578

Asia WGS AF: 0.00144 AC: 5 AN: 3478

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Generalized epilepsy-paroxysmal dyskinesia syndrome Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.31
Cadd	Benign	16
Dann	Benign	0.79

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: rs80189498; hg19: chr10-78645259;