3-8733992-T-C

Position:

• chr3-8733992-T-C

Variant summary

Our verdict is Pathogenic. Variant got 15 ACMG points: 15P and 0B. PVS1_Strong PM2 PP3 PP5_Very_Strong

The NM_033337.3(CAV3):​c.114+2T>C variant causes a splice donor change. The variant allele was found at a frequency of 0.000000706 in 1,416,504 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 7.1e-7 (0 hom.)
• Consequence: CAV3 NM_033337.3 splice_donor
• Scores: Splicing: ADA: 0.9909
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2 O:1
• Conservation: PhyloP100: 5.14

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 Pathogenic. Variant got 15 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.4122807 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.9, offset of 41, new splice context is: cagGTttgc. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, max_spliceai. No scorers claiming Uncertain. Scorers claiming Benign: dbscSNV1_RF.
• PP5: Variant 3-8733992-T-C is Pathogenic according to our data. Variant chr3-8733992-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 31740.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-8733992-T-C is described in Lovd as [Pathogenic]. Variant chr3-8733992-T-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CAV3	NM_033337.3	c.114+2T>C		splice_donor_variant		ENST00000343849.3
CAV3	NM_001234.5	c.114+2T>C		splice_donor_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CAV3	ENST00000343849.3	c.114+2T>C		splice_donor_variant		1	NM_033337.3	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 7.06e-7 AC: 1 AN: 1416504 Hom.: 0 Cov.: 25 AF XY: 0.00 AC XY: 0 AN XY: 707394

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: 9.34e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Elevated circulating creatine kinase concentration;C1832560:Rippling muscle disease 2;C2678485:Long QT syndrome 9;C3280443:Distal myopathy, Tateyama type;C3495498:Hypertrophic cardiomyopathy 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Nov 24, 2021

- -

Long QT syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 30, 2020

Nucleotide substitutions within the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Experimental studies have shown that this variant disrupts mRNA splicing and affects protein function (PMID: 16730439, 21294223). This variant has been observed in the heterozygous and homozygous state in individuals affected with clinical features of caveolinopathies (PMID: 26185955, 16730439). ClinVar contains an entry for this variant (Variation ID: 31740). This variant is not present in population databases (ExAC no frequency). 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, but it affects a nucleotide within the consensus splice site of the intron. For these reasons, this variant has been classified as Pathogenic. -

not provided Other:1

not provided, no classification provided

curation

Leiden Muscular Dystrophy (CAV3)

Apr 15, 2012

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.27
CADD	Pathogenic	35
DANN	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Uncertain	0.94	D
MutationTaster	Benign	1.0	D;D
GERP RS		5.3

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.99
dbscSNV1_RF	Benign	0.64
SpliceAI score (max)		0.96		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.96		Position offset: 39
DS_DL_spliceai		0.90		Position offset: -2

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

Publications

LitVar

Other links and lift over

dbSNP: rs116840787; hg19: chr3-8775678;