rs1555558553

Positions:

• chr17-50607905-A-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Moderate PP5_Moderate

The NM_018896.5(CACNA1G):​c.4591A>G​(p.Met1531Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: CACNA1G NM_018896.5 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 9.32

Genes affected

CACNA1G (HGNC:1394): (calcium voltage-gated channel subunit alpha1 G) Voltage-sensitive 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, gene expression, cell motility, cell division, and cell death. This gene encodes a T-type, low-voltage activated calcium channel. The T-type channels generate currents that are both transient, owing to fast inactivation, and tiny, owing to small conductance. T-type channels are thought to be involved in pacemaker activity, low-threshold calcium spikes, neuronal oscillations and resonance, and rebound burst firing. Many alternatively spliced transcript variants encoding different isoforms have been described for this gene. [provided by RefSeq, Sep 2011]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.845
• PP5: Variant 17-50607905-A-G is Pathogenic according to our data. Variant chr17-50607905-A-G is described in ClinVar as [Pathogenic]. Clinvar id is 559581.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CACNA1G	NM_018896.5	c.4591A>G	p.Met1531Val	missense_variant	25/38	ENST00000359106.10	NP_061496.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CACNA1G	ENST00000359106.10	c.4591A>G	p.Met1531Val	missense_variant	25/38	1	NM_018896.5	ENSP00000352011.5
CACNA1G	ENST00000507510.6	c.4591A>G	p.Met1531Val	missense_variant	25/37	1		ENSP00000423112.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Spinocerebellar ataxia 42, early-onset, severe, with neurodevelopmental deficits Pathogenic:2

Pathogenic, no assertion criteria provided	literature only	OMIM	Aug 14, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	Victorian Clinical Genetics Services, Murdoch Childrens Research Institute	Jun 11, 2020	Based on the classification scheme VCGS_Germline_v1.1.1, this variant is classified as Pathogenic. Following criteria are met: 0105 - The mechanism of disease for this gene is not clearly established however both loss- and gain-of-function have been reported (PMID: 31217264). (N) 0107 - This gene is known to be associated with autosomal dominant disease. (N) 0200 - Variant is predicted to result in a missense amino acid change from methionine to valine (exon 25). (N) 0251 - Variant is heterozygous. (N) 0301 - Variant is absent from gnomAD. (P) 0502 - Missense variant with conflicting in-silico predictions and/or uninformative conservation. (N) 0603 - Missense variant located within the transmembrane S6 of repeat III in a region that is highly intolerant to missense variation (high constraint region). (P) 0705 - No comparable variants have previous evidence for pathogenicity. (N) 0801 - Strong previous evidence of pathogenicity in unrelated individuals. This variant has been reported as de novo in 3 patients with early onset CACNA1G-related disorders (PMID: 31836334; 29878067; 30792901) (P) 1002 - Moderate functional evidence supporting abnormal protein function. Functional studies demonstrated altered electrophysiological behaviour and increased calcium influx (PMID: 29878067) (P) 1208 - Inheritance information for this variant is not currently available. (N) Legend: (P) - Pathogenic, (N) - Neutral, (B) - Benign -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.92
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.44
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.86	.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;D;.
Eigen	Uncertain	0.47
Eigen_PC	Uncertain	0.52
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.59	D
MetaRNN	Pathogenic	0.85	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Benign	1.4	.;.;.;.;.;L;L;L;L;.;L;L;L;L;L;L;L;L;L;.
PrimateAI	Pathogenic	0.87	D
PROVEAN	Uncertain	-3.5	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.95
Sift	Uncertain	0.015	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
Sift4G	Uncertain	0.0020	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
Polyphen		0.66, 0.94	.;.;.;.;P;.;.;.;.;.;.;.;.;.;.;.;.;.;P;.
Vest4		0.62
MutPred		0.76		.;.;.;.;.;Loss of helix (P = 0.0237);Loss of helix (P = 0.0237);Loss of helix (P = 0.0237);Loss of helix (P = 0.0237);.;Loss of helix (P = 0.0237);Loss of helix (P = 0.0237);Loss of helix (P = 0.0237);Loss of helix (P = 0.0237);Loss of helix (P = 0.0237);Loss of helix (P = 0.0237);Loss of helix (P = 0.0237);Loss of helix (P = 0.0237);Loss of helix (P = 0.0237);.;
MVP		0.99
MPC		1.9
ClinPred		0.98	D
GERP RS		4.8
Varity_R		0.78
gMVP		0.95

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: rs1555558553; hg19: chr17-48685266;