rs886038855

Positions:

• chr10-88948848-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_001613.4(ACTA2):​c.83C>T​(p.Ala28Val) variant causes a missense change involving the alteration of a 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A28D) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ACTA2 NM_001613.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 10.0

Genes affected

ACTA2 (HGNC:130): (actin alpha 2, smooth muscle) This gene encodes one of six different actin proteins. Actins are highly conserved proteins that are involved in cell motility, structure, integrity, and intercellular signaling. The encoded protein is a smooth muscle actin that is involved in vascular contractility and blood pressure homeostasis. Mutations in this gene cause a variety of vascular diseases, such as thoracic aortic disease, coronary artery disease, stroke, and Moyamoya disease, as well as multisystemic smooth muscle dysfunction syndrome. [provided by RefSeq, Sep 2017]

STAMBPL1 (HGNC:24105): (STAM binding protein like 1) Predicted to enable Lys63-specific deubiquitinase activity and thiol-dependent deubiquitinase. Predicted to be involved in protein K63-linked deubiquitination. Located in membrane. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), ACTA2. . Trascript score misZ 4.6117 (greater than threshold 3.09). GenCC has associacion of gene with familial thoracic aortic aneurysm and aortic dissection, connective tissue disorder, aortic aneurysm, familial thoracic 6, multisystemic smooth muscle dysfunction syndrome, Moyamoya disease 5.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.861

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ACTA2	NM_001613.4	c.83C>T	p.Ala28Val	missense_variant	2/9	ENST00000224784.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ACTA2	ENST00000224784.10	c.83C>T	p.Ala28Val	missense_variant	2/9	1	NM_001613.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Dec 05, 2023	Variant of Uncertain Significance due to insufficient evidence: This missense variant replaces alanine with valine at codon 28 of the ACTA2 protein. Computational prediction tools and conservation analyses suggest that this variant may have deleterious impact on the protein function. Computational splicing tools suggest that this variant may not impact RNA splicing. To our knowledge, functional assays have not been performed for this variant nor has this variant been reported in individuals affected with cardiovascular disorders in the literature. This variant is rare in the general population and has been identified in 0/277264 chromosomes by the Genome Aggregation Database (gnomAD). Available evidence is insufficient to determine the role of this variant in disease conclusively. -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jul 23, 2021	The p.A28V variant (also known as c.83C>T), located in coding exon 1 of the ACTA2 gene, results from a C to T substitution at nucleotide position 83. The alanine at codon 28 is replaced by valine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Aortic aneurysm, familial thoracic 6 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 09, 2018

This sequence change replaces alanine with valine at codon 28 of the ACTA2 protein (p.Ala28Val). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and valine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with ACTA2-related disease. ClinVar contains an entry for this variant (Variation ID: 263583). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.28	D
BayesDel_noAF	Pathogenic	0.16
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.65	D;T;T
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.91
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.83	T;.;T
M_CAP	Pathogenic	0.38	D
MetaRNN	Pathogenic	0.86	D;D;D
MetaSVM	Pathogenic	0.90	D
MutationAssessor	Uncertain	2.2	M;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.89	D
PROVEAN	Benign	-1.9	N;N;N
REVEL	Pathogenic	0.75
Sift4G	Uncertain	0.040	D;.;.
Polyphen		0.74	P;.;.
Vest4		0.64
MutPred		0.74		Loss of disorder (P = 0.0797);Loss of disorder (P = 0.0797);Loss of disorder (P = 0.0797);
MVP		0.87
ClinPred		0.94	D
GERP RS		5.7
Varity_R		0.82
gMVP		0.91

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

Publications

LitVar

Other links and lift over

dbSNP: rs886038855; hg19: chr10-90708605;