chr12-2605078-C-T

Position:

• chr12-2605078-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_000719.7(CACNA1C):​c.2961-3C>T variant causes a splice region, splice polypyrimidine tract, intron 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. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CACNA1C NM_000719.7 splice_region, splice_polypyrimidine_tract, intron
• Scores: Splicing: ADA: 0.9602
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.13

Genes affected

CACNA1C (HGNC:1390): (calcium voltage-gated channel subunit alpha1 C) This gene encodes an alpha-1 subunit of a voltage-dependent calcium channel. Calcium channels mediate the influx of calcium ions into the cell upon membrane polarization. The alpha-1 subunit consists of 24 transmembrane segments and forms the pore through which ions pass into the cell. The calcium channel consists of a complex of alpha-1, alpha-2/delta, beta, and gamma subunits in a 1:1:1:1 ratio. There are multiple isoforms of each of these proteins, either encoded by different genes or the result of alternative splicing of transcripts. The protein encoded by this gene binds to and is inhibited by dihydropyridine. Alternative splicing results in many transcript variants encoding different proteins. Some of the predicted proteins may not produce functional ion channel subunits. [provided by RefSeq, Oct 2012]

CACNA1C-AS3 (HGNC:40117): (CACNA1C antisense RNA 3)

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.15).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CACNA1C	NM_000719.7	c.2961-3C>T		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000399655.6
CACNA1C	NM_001167623.2	c.2961-3C>T		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000399603.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CACNA1C	ENST00000399603.6	c.2961-3C>T		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		5	NM_001167623.2
CACNA1C	ENST00000399655.6	c.2961-3C>T		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		1	NM_000719.7
CACNA1C-AS3	ENST00000543559.1	n.21-1305G>A		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1460358 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726564

Gnomad4 AFR exome AF: 0.00

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Long QT syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 14, 2023

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. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 2091291). This variant has not been reported in the literature in individuals affected with CACNA1C-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change falls in intron 22 of the CACNA1C gene. It does not directly change the encoded amino acid sequence of the CACNA1C protein. It affects a nucleotide within the consensus splice site. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.15
CADD	Benign	16
DANN	Uncertain	0.98

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.96
dbscSNV1_RF	Benign	0.29
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

No publications associated with this variant yet.

Other links and lift over

hg19: chr12-2714244;