chr3-8733881-T-C

Variant names:

• chr3-8733881-T-C
• rs375301072
• NM_033337.3:c.5T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1 PM2 PP2 PP3_Moderate

The NM_033337.3(CAV3):​c.5T>C​(p.Met2Thr) variant causes a missense change involving the alteration of a non-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 Uncertain significance (★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: CAV3 NM_033337.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.42
• 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]

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

SSUH2 Gene-Disease associations (from GenCC):

• dentin dysplasia type I

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM1: In a topological_domain Cytoplasmic (size 82) in uniprot entity CAV3_HUMAN there are 14 pathogenic changes around while only 6 benign (70%) in NM_033337.3
• PM2: Very rare variant in population databases, with high coverage
• 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, 0.873

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CAV3	NM_033337.3	c.5T>C	p.Met2Thr	missense_variant	Exon 1 of 2	ENST00000343849.3	NP_203123.1
CAV3	NM_001234.5	c.5T>C	p.Met2Thr	missense_variant	Exon 1 of 3		NP_001225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CAV3	ENST00000343849.3	c.5T>C	p.Met2Thr	missense_variant	Exon 1 of 2	1	NM_033337.3	ENSP00000341940.2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 31

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Long QT syndrome Uncertain:1

Jan 26, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces methionine with threonine at codon 2 of the CAV3 protein (p.Met2Thr). The methionine residue is highly conserved and there is a moderate physicochemical difference between methionine and threonine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with CAV3-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C65"). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.25
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.15
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.51	D;D
Eigen	Uncertain	0.31
Eigen_PC	Uncertain	0.25
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Benign	0.44	.;T
M_CAP	Pathogenic	0.34	D
MetaRNN	Pathogenic	0.87	D;D
MetaSVM	Uncertain	0.58	D
MutationAssessor	Pathogenic	2.9	M;M
PhyloP100		3.4
PrimateAI	Uncertain	0.71	T
PROVEAN	Benign	-1.7	N;N
REVEL	Pathogenic	0.78
Sift	Uncertain	0.0030	D;D
Sift4G	Uncertain	0.027	D;D
Polyphen		0.91	P;P
Vest4		0.78
MVP		1.0
MPC		0.90
ClinPred		0.93	D
GERP RS		3.7
PromoterAI		-0.0064	Neutral
Varity_R		0.55
gMVP		0.88
Mutation Taster		=83/17	polymorphism

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: rs375301072; hg19: chr3-8775567;