3-8733961-C-T

Variant names:

• chr3-8733961-C-T
• rs116840785
• NM_033337.3:c.85C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM2 PP2 PP3_Strong

The NM_033337.3(CAV3):​c.85C>T​(p.Pro29Ser) variant causes a missense change. 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P29T) has been classified 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: 5.07
• 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 9 ACMG points.

• PM1: In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain 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, 0.989

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CAV3	NM_033337.3	c.85C>T	p.Pro29Ser	missense_variant	Exon 1 of 2	ENST00000343849.3	NP_203123.1
CAV3	NM_001234.5	c.85C>T	p.Pro29Ser	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.85C>T	p.Pro29Ser	missense_variant	Exon 1 of 2	1	NM_033337.3	ENSP00000341940.2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Long QT syndrome Uncertain:1

Jul 03, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 526918). 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). This sequence change replaces proline, which is neutral and non-polar, with serine, which is neutral and polar, at codon 29 of the CAV3 protein (p.Pro29Ser). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.87
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.44
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.95	D;D
Eigen	Pathogenic	0.80
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Pathogenic	0.97	.;D
M_CAP	Pathogenic	0.48	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.3	M;M
PhyloP100		5.1
PrimateAI	Uncertain	0.69	T
PROVEAN	Pathogenic	-7.4	D;D
REVEL	Pathogenic	0.93
Sift	Uncertain	0.0020	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;D
Vest4		0.82
MutPred		0.90		Loss of methylation at K30 (P = 0.0806);Loss of methylation at K30 (P = 0.0806);
MVP		1.0
MPC		1.4
ClinPred		1.0	D
GERP RS		5.2
PromoterAI		0.042	Neutral
Varity_R		0.80
gMVP		0.89
Mutation Taster		=29/71	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: rs116840785; hg19: chr3-8775647;