rs746972765

Positions:

• chr10-88941252-C-T

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PM2 PP2 PP3_Moderate PP5_Very_Strong

The NM_001613.4(ACTA2):​c.593G>A​(p.Arg198His) 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 Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: ACTA2 NM_001613.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5 U:1
• Conservation: PhyloP100: 7.86

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]

ACTA2 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 13 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, 0.918
• PP5: Variant 10-88941252-C-T is Pathogenic according to our data. Variant chr10-88941252-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 264311.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ACTA2	NM_001613.4	c.593G>A	p.Arg198His	missense_variant	6/9	ENST00000224784.10	NP_001604.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ACTA2	ENST00000224784.10	c.593G>A	p.Arg198His	missense_variant	6/9	1	NM_001613.4	ENSP00000224784.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Pathogenic:3

Likely pathogenic, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Aug 13, 2019	The p.Arg198His variant in ACTA2 has been reported in at least 6 individuals with aortic aneurysms or dissections and segregated with disease in 5 affected family members (Regalado 2015; Color Genomics personal communication). It was absent from large population studies. This variant has also been reported in ClinVar (Variation ID 264311). Additionally, a different variant at this codon (p.Arg198Cys) has been reported in 2 individuals with aortic aneurysms or dissections (Regalado 2015). Computational prediction tools and conservation analysis suggest that the p.Arg198His variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, although additional studies are required to fully establish its clinical significance, this variant meets criteria to be classified as likely pathogenic for autosomal dominant familial thoracic aortic aneurysm and dissection (FTAAD). ACMG/AMP criteria applied: PM2, PS4_Moderate, PP1_Moderate, PP3. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Feb 19, 2019	The p.R198H variant (also known as c.593G>A), located in coding exon 5 of the ACTA2 gene, results from a G to A substitution at nucleotide position 593. The arginine at codon 198 is replaced by histidine, an amino acid with highly similar properties. In one family, this variant was described in three heterozygous individuals, two of whom were reported to have had aortic dissection and/or surgical repair of aortic aneurysm (Regalado ES et al, Circ Cardiovasc Genet 2015 Jun; 8(3):457-64). In the same study, an alteration affecting the same codon (c.592C>T p.R198C) was described in two unrelated heterozygous individuals, both of whom had dissection and/or surgical repair of aortic aneurysm. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Mar 11, 2020	This missense variant replaces arginine with histidine at codon 198 of the ACTA2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in multiple individuals affected with and/or having family history of aortic dissections or aneurysms (PMID: 25759435 and Color internal data). A different variant at this position (p.Arg198Cys) has also been observed in individuals affected with aortic events (PMID: 25759435). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Although additional studies are required to fully establish its clinical significance, this variant is classified as Likely Pathogenic based on the available evidence. -

Aortic aneurysm, familial thoracic 6;C3151201:Multisystemic smooth muscle dysfunction syndrome;C3279690:Moyamoya disease 5 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Juno Genomics, Hangzhou Juno Genomics, Inc

-

PM2_Supporting+PP3_Moderate+PP2+PP4+PP1 -

Aortic aneurysm, familial thoracic 6 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 01, 2023

For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Arg198 amino acid residue in ACTA2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 25759435; Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt ACTA2 protein function. ClinVar contains an entry for this variant (Variation ID: 264311). This missense change has been observed in individuals with aneurysm and/or dissection (PMID: 25759435; Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 198 of the ACTA2 protein (p.Arg198His). -

not provided Uncertain:1

Uncertain significance, flagged submission

clinical testing

AiLife Diagnostics, AiLife Diagnostics

Dec 16, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.33
CADD	Pathogenic	32
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.79	D
Eigen	Uncertain	0.45
Eigen_PC	Uncertain	0.57
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.85	D
M_CAP	Pathogenic	0.34	D
MetaRNN	Pathogenic	0.92	D
MetaSVM	Uncertain	0.73	D
MutationAssessor	Pathogenic	3.7	H
PrimateAI	Pathogenic	0.90	D
PROVEAN	Uncertain	-3.6	D
REVEL	Pathogenic	0.85
Sift4G	Uncertain	0.023	D
Polyphen		0.034	B
Vest4		0.70
MutPred		0.92		Loss of phosphorylation at T196 (P = 0.0878);
MVP		0.95
ClinPred		1.0	D
GERP RS		5.9
Varity_R		0.85
gMVP		0.93

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: rs746972765; hg19: chr10-90701009;