chr3-8733898-G-A

Variant names:

• chr3-8733898-G-A
• rs2124977121
• NM_033337.3:c.22G>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 5P and 2B. PM1 PM2 PP2 BP4_Moderate

The NM_033337.3(CAV3):​c.22G>A​(p.Asp8Asn) 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 benign outcome for this variant. 16/22 in silico tools predict a benign 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: 2.52
• 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: Uncertain_significance. The variant received 3 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 9 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.23366463).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CAV3	NM_033337.3	c.22G>A	p.Asp8Asn	missense_variant	Exon 1 of 2	ENST00000343849.3	NP_203123.1
CAV3	NM_001234.5	c.22G>A	p.Asp8Asn	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.22G>A	p.Asp8Asn	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

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Long QT syndrome 9 Uncertain:1

Mar 09, 2021

Breda Genetics srl

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on allele frequency, in-silico prediction scores and a certain overlap with the clinical phenotype, we interpreted this variant at least as of uncertain significance. The lack of one or more of the following features has discouraged further investigations: lack of a possible second hit in autosomal recessive conditions, presence of healthy controls in databases for autosomal dominant conditions, presence of unmatching cardinal clinical features in the patient or in the known gene-disease association, and/or variant type outside the known gene mutational spectrum. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.079
BayesDel_addAF	Benign	-0.0041	T
BayesDel_noAF	Benign	-0.24
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Benign	0.25	T;T
Eigen	Benign	-0.085
Eigen_PC	Benign	0.052
FATHMM_MKL	Uncertain	0.76	D
LIST_S2	Benign	0.82	.;T
M_CAP	Benign	0.047	D
MetaRNN	Benign	0.23	T;T
MetaSVM	Uncertain	0.32	D
MutationAssessor	Benign	-0.69	N;N
PhyloP100		2.5
PrimateAI	Benign	0.46	T
PROVEAN	Benign	0.12	N;N
REVEL	Benign	0.26
Sift	Benign	0.21	T;T
Sift4G	Benign	0.43	T;T
Polyphen		0.083	B;B
Vest4		0.29
MutPred		0.39		Loss of helix (P = 0.1299);Loss of helix (P = 0.1299);
MVP		1.0
MPC		0.56
ClinPred		0.62	D
GERP RS		5.2
PromoterAI		-0.0031	Neutral
Varity_R		0.077
gMVP		0.70
Mutation Taster		=86/14	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: rs2124977121; hg19: chr3-8775584; COSMIC: COSV59561614;