10-88935236-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM5 PP2 PP3_Moderate

The NM_001613.4(ACTA2):c.1121G>A(p.Arg374His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,060 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R374C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: ACTA2 NM_001613.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 7.83

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]

ACTA2-AS1 (HGNC:45169): (ACTA2 antisense RNA 1)

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.

• PM5: Other missense variant is known to change same aminoacid residue: Variant chr10-88935237-G-A is described in Lovd as [Likely_pathogenic].
• PP2: Missense variant where missense usually causes diseases, ACTA2
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.871

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ACTA2	NM_001613.4	c.1121G>A	p.Arg374His	missense_variant	9/9	ENST00000224784.10
ACTA2-AS1	NR_125373.1	n.861C>T		non_coding_transcript_exon_variant	3/5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ACTA2	ENST00000224784.10	c.1121G>A	p.Arg374His	missense_variant	9/9	1	NM_001613.4	P1
ACTA2-AS1	ENST00000437930.4	n.902C>T		non_coding_transcript_exon_variant	3/5	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251242 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135784

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461060 Hom.: 0 Cov.: 30 AF XY: 0.00000550 AC XY: 4 AN XY: 726860

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000540

Gnomad4 OTH exome AF: 0.00

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:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Feb 05, 2024

This missense variant replaces arginine with histidine at codon 374 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 not been reported in individuals affected with ACTA2-related disorders in the literature. This variant has been identified in 1/251242 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Mar 11, 2021

Has not been previously published as pathogenic or benign to our knowledge; Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function -

Aortic aneurysm, familial thoracic 6 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 17, 2023

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. 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: 1310808). This variant has not been reported in the literature in individuals affected with ACTA2-related conditions. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 374 of the ACTA2 protein (p.Arg374His). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.34
Cadd	Pathogenic	33
Dann	Uncertain	0.98
DEOGEN2	Uncertain	0.78	D
Eigen	Uncertain	0.43
Eigen_PC	Uncertain	0.52
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.90	D
M_CAP	Pathogenic	0.31	D
MetaRNN	Pathogenic	0.87	D
MetaSVM	Uncertain	0.76	D
MutationAssessor	Pathogenic	3.4	M
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.92	D
PROVEAN	Benign	-1.8	N
REVEL	Pathogenic	0.82
Sift4G	Uncertain	0.023	D
Polyphen		0.011	B
Vest4		0.76
MutPred		0.85		Gain of ubiquitination at K375 (P = 0.044);
MVP		0.95
ClinPred		0.77	D
GERP RS		5.6
Varity_R		0.88
gMVP		0.65

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: rs1370988055; hg19: chr10-90694993;