3-8733995-G-C

Position:

• chr3-8733995-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_033337.3(CAV3):​c.114+5G>C variant causes a splice donor 5th base, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000715 in 1,398,866 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 predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 7.1e-7 (0 hom.)
• Consequence: CAV3 NM_033337.3 splice_donor_5th_base, intron
• Scores: Splicing: ADA: 0.9985
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.25

Genes affected

CAV3 (HGNC:1529): (caveolin 3) This gene encodes a caveolin family member, which functions as a component of the caveolae plasma membranes found in most cell types. Caveolin proteins are proposed to be scaffolding proteins for organizing and concentrating certain caveolin-interacting molecules. Mutations identified in this gene lead to interference with protein oligomerization or intra-cellular routing, disrupting caveolae formation and resulting in Limb-Girdle muscular dystrophy type-1C (LGMD-1C), hyperCKemia or rippling muscle disease (RMD). Alternative splicing has been identified for this locus, with inclusion or exclusion of a differentially spliced intron. In addition, transcripts utilize multiple polyA sites and contain two potential translation initiation sites. [provided by RefSeq, Jul 2008]

SSUH2 (HGNC:24809): (ssu-2 homolog) Involved in odontogenesis. Located in cytoplasm and nucleus. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CAV3	NM_033337.3	c.114+5G>C		splice_donor_5th_base_variant, intron_variant		ENST00000343849.3
CAV3	NM_001234.5	c.114+5G>C		splice_donor_5th_base_variant, intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CAV3	ENST00000343849.3	c.114+5G>C		splice_donor_5th_base_variant, intron_variant		1	NM_033337.3	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 7.15e-7 AC: 1 AN: 1398866 Hom.: 0 Cov.: 23 AF XY: 0.00 AC XY: 0 AN XY: 699712

Gnomad4 AFR exome AF: 0.0000314

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.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Long QT syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 13, 2022

This sequence change falls in intron 1 of the CAV3 gene. It does not directly change the encoded amino acid sequence of the CAV3 protein. It affects a nucleotide within the consensus splice site. 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 create or strengthen a splice site. ClinVar contains an entry for this variant (Variation ID: 526971). This variant has not been reported in the literature in individuals affected with CAV3-related conditions. This variant is not present in population databases (gnomAD no frequency). -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 26, 2023

The c.114+5G>C intronic variant results from a G to C substitution 5 nucleotides after coding exon 1 in the CAV3 gene. This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will result in the creation or strengthening of a novel splice donor site. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.29
CADD	Benign	23
DANN	Benign	0.92

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.89
SpliceAI score (max)		0.55		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.55		Position offset: 36

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1354029651; hg19: chr3-8775681;