10-77184922-A-G

Variant names:

• chr10-77184922-A-G
• rs201637862
• NM_001161352.2:c.603-6T>C

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Moderate BP6_Moderate

The NM_001161352.2(KCNMA1):​c.603-6T>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000707 in 1,415,030 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: not found (cov: 32)
  • Exomes 𝑓: 7.1e-7 (0 hom.)
• Consequence: KCNMA1 NM_001161352.2 splice_region, intron
• Scores: Splicing: ADA: 0.0002914
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 2.60
• Publications: 0 publications found

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)

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.42).
• BP6: Variant 10-77184922-A-G is Benign according to our data. Variant chr10-77184922-A-G is described in ClinVar as Likely_benign. ClinVar VariationId is 464302.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001161352.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNMA1	NM_001161352.2	MANE Select	c.603-6T>C		splice_region intron	N/A	NP_001154824.1
	KCNMA1	NM_001437422.1		c.735-6T>C		splice_region intron	N/A	NP_001424351.1
	KCNMA1	NM_001161353.2		c.603-6T>C		splice_region intron	N/A	NP_001154825.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNMA1	ENST00000286628.14	TSL:1 MANE Select	c.603-6T>C		splice_region intron	N/A	ENSP00000286628.8
	KCNMA1	ENST00000626620.3	TSL:1	c.603-6T>C		splice_region intron	N/A	ENSP00000485867.1
	KCNMA1	ENST00000639406.1	TSL:1	c.603-6T>C		splice_region intron	N/A	ENSP00000491732.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 7.07e-7 AC: 1 AN: 1415030 Hom.: 0 Cov.: 24 AF XY: 0.00000141 AC XY: 1 AN XY: 706774

African (AFR) AF: 0.00 AC: 0 AN: 32452

American (AMR) AF: 0.00 AC: 0 AN: 44640

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25854

East Asian (EAS) AF: 0.00 AC: 0 AN: 39390

South Asian (SAS) AF: 0.00 AC: 0 AN: 85290

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53258

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5670

European-Non Finnish (NFE) AF: 9.35e-7 AC: 1 AN: 1069626

Other (OTH) AF: 0.00 AC: 0 AN: 58850

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Generalized epilepsy-paroxysmal dyskinesia syndrome Benign:1

Aug 11, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.42
CADD	Benign	13
DANN	Benign	0.83
PhyloP100		2.6
PromoterAI		0.037	Neutral

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00029
dbscSNV1_RF	Benign	0.042
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

Other links and lift over

dbSNP: rs201637862; hg19: chr10-78944680;