3-8745665-C-T

Variant names:

• chr3-8745665-C-T
• rs1553614440
• NM_033337.3:c.254C>T

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP2 PP3_Strong

The NM_033337.3(CAV3):​c.254C>T​(p.Ala85Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,818 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. A85T) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CAV3 NM_033337.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.50
• Publications: 0 publications found

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]

OXTR (HGNC:8529): (oxytocin receptor) The protein encoded by this gene belongs to the G-protein coupled receptor family and acts as a receptor for oxytocin. Its activity is mediated by G proteins which activate a phosphatidylinositol-calcium second messenger system. The oxytocin-oxytocin receptor system plays an important role in the uterus during parturition. [provided by RefSeq, Jul 2008]

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 18 uncertain in NM_033337.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-8745664-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 8294.Status of the report is no_assertion_criteria_provided, 0 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 17 curated pathogenic missense variants (we use a threshold of 10). The gene has 2 curated benign missense variants. Gene score misZ: 0.83011 (below the threshold of 3.09). Trascript score misZ: 0.9876 (below the threshold of 3.09). GenCC associations: The gene is linked to rippling muscle disease 2, hypertrophic cardiomyopathy 1, long QT syndrome 9, distal myopathy, Tateyama type, inherited rippling muscle disease, Brugada syndrome, autosomal dominant limb-girdle muscular dystrophy type 1C, caveolinopathy, long QT syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.982

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CAV3	NM_033337.3	c.254C>T	p.Ala85Val	missense_variant	Exon 2 of 2	ENST00000343849.3	NP_203123.1
CAV3	NM_001234.5	c.254C>T	p.Ala85Val	missense_variant	Exon 2 of 3		NP_001225.1
OXTR	XR_007095681.1	n.1885-3063G>A		intron_variant	Intron 4 of 4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CAV3	ENST00000343849.3	c.254C>T	p.Ala85Val	missense_variant	Exon 2 of 2	1	NM_033337.3	ENSP00000341940.2
CAV3	ENST00000397368.2	c.254C>T	p.Ala85Val	missense_variant	Exon 2 of 3	1		ENSP00000380525.2
CAV3	ENST00000472766.1	n.155+11675C>T		intron_variant	Intron 1 of 2	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461818 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727206

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.00 AC: 0 AN: 86242

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53404

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111984

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

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 Uncertain:1

Sep 15, 2021

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Long QT syndrome Uncertain:1

May 09, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a CAV3-related disease. This sequence change replaces alanine with valine at codon 85 of the CAV3 protein (p.Ala85Val). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and valine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.52
CADD	Pathogenic	31
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D;D
Eigen	Pathogenic	0.71
Eigen_PC	Uncertain	0.59
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.96	.;D
M_CAP	Pathogenic	0.52	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.5	H;H
PhyloP100		7.5
PrimateAI	Uncertain	0.74	T
PROVEAN	Uncertain	-3.8	D;D
REVEL	Pathogenic	0.93
Sift	Uncertain	0.0010	D;D
Sift4G	Uncertain	0.0040	D;D
Polyphen		1.0	D;D
Vest4		0.78
MutPred		0.88		Loss of helix (P = 0.0444);Loss of helix (P = 0.0444);
MVP		1.0
MPC		1.3
ClinPred		1.0	D
GERP RS		4.6
Varity_R		0.94
gMVP		0.95
Mutation Taster		=28/72	disease causing

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: rs1553614440; hg19: chr3-8787351;