chr19-13298827-G-T

Variant names:

• chr19-13298827-G-T
• rs1318353774
• NM_001127222.2:c.2806C>A

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_001127222.2(CACNA1A):​c.2806C>A​(p.Gln936Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q936H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CACNA1A NM_001127222.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.53
• Publications: 0 publications found

Genes affected

CACNA1A (HGNC:1388): (calcium voltage-gated channel subunit alpha1 A) Voltage-dependent calcium channels mediate the entry of calcium ions into excitable cells, and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, and gene expression. Calcium channels are multisubunit complexes composed of alpha-1, beta, alpha-2/delta, and gamma subunits. The channel activity is directed by the pore-forming alpha-1 subunit, whereas, the others act as auxiliary subunits regulating this activity. The distinctive properties of the calcium channel types are related primarily to the expression of a variety of alpha-1 isoforms, alpha-1A, B, C, D, E, and S. This gene encodes the alpha-1A subunit, which is predominantly expressed in neuronal tissue. Mutations in this gene are associated with 2 neurologic disorders, familial hemiplegic migraine and episodic ataxia 2. This gene also exhibits polymorphic variation due to (CAG)n-repeats. Multiple transcript variants encoding different isoforms have been found for this gene. In one set of transcript variants, the (CAG)n-repeats occur in the 3' UTR, and are not associated with any disease. But in another set of variants, an insertion extends the coding region to include the (CAG)n-repeats which encode a polyglutamine tract. Expansion of the (CAG)n-repeats from the normal 4-18 to 21-33 in the coding region is associated with spinocerebellar ataxia 6. [provided by RefSeq, Jul 2016]

CACNA1A Gene-Disease associations (from GenCC):

• episodic ataxia type 2

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• undetermined early-onset epileptic encephalopathy

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, Illumina
• developmental and epileptic encephalopathy, 42

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• migraine, familial hemiplegic, 1

  Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• spinocerebellar ataxia type 6

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet
• benign paroxysmal torticollis of infancy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial or sporadic hemiplegic migraine

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Lennox-Gastaut syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.28013816).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001127222.2. 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
	CACNA1A	NM_001127222.2	MANE Select	c.2806C>A	p.Gln936Lys	missense	Exon 19 of 47	NP_001120694.1
	CACNA1A	NM_001127221.2	MANE Plus Clinical	c.2809C>A	p.Gln937Lys	missense	Exon 19 of 47	NP_001120693.1
	CACNA1A	NM_023035.3		c.2818C>A	p.Gln940Lys	missense	Exon 19 of 48	NP_075461.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CACNA1A	ENST00000360228.11	TSL:1 MANE Select	c.2806C>A	p.Gln936Lys	missense	Exon 19 of 47	ENSP00000353362.5
	CACNA1A	ENST00000638009.2	TSL:1 MANE Plus Clinical	c.2809C>A	p.Gln937Lys	missense	Exon 19 of 47	ENSP00000489913.1
	CACNA1A	ENST00000638029.1	TSL:5	c.2818C>A	p.Gln940Lys	missense	Exon 19 of 48	ENSP00000489829.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1423492 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 707194

African (AFR) AF: 0.00 AC: 0 AN: 31214

American (AMR) AF: 0.00 AC: 0 AN: 42480

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25230

East Asian (EAS) AF: 0.00 AC: 0 AN: 37734

South Asian (SAS) AF: 0.00 AC: 0 AN: 82824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 37138

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4796

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1103004

Other (OTH) AF: 0.00 AC: 0 AN: 59072

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Mar 02, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.2809C>A (p.Q937K) alteration is located in exon 19 (coding exon 19) of the CACNA1A gene. This alteration results from a C to A substitution at nucleotide position 2809, causing the glutamine (Q) at amino acid position 937 to be replaced by a lysine (K). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Uncertain	-0.040
CADD	Benign	20
DANN	Benign	0.66
DEOGEN2	Benign	0.023	T
Eigen	Benign	-0.66
Eigen_PC	Benign	-0.60
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Benign	0.85	T
M_CAP	Pathogenic	0.89	D
MetaRNN	Benign	0.28	T
MetaSVM	Uncertain	-0.20	T
MutationAssessor	Benign	0.81	L
PhyloP100		2.5
PrimateAI	Pathogenic	0.87	D
PROVEAN	Benign	-1.1	N
REVEL	Uncertain	0.48
Sift	Benign	0.28	T
Sift4G	Benign	0.60	T
Vest4		0.14
MutPred		0.22		Gain of methylation at Q937 (P = 0.012)
MVP		0.96
MPC		1.5
ClinPred		0.12	T
GERP RS		3.8
Varity_R		0.14
gMVP		0.58
Mutation Taster		=90/10	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

Other links and lift over

dbSNP: rs1318353774; hg19: chr19-13409641; COSMIC: COSV100800684;