12-51915407-G-C

Position:

• chr12-51915407-G-C

Variant summary

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

The NM_000020.3(ACVRL1):​c.955G>C​(p.Gly319Arg) 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 pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: ACVRL1 NM_000020.3 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 3.41

Genes affected

ACVRL1 (HGNC:175): (activin A receptor like type 1) This gene encodes a type I cell-surface receptor for the TGF-beta superfamily of ligands. It shares with other type I receptors a high degree of similarity in serine-threonine kinase subdomains, a glycine- and serine-rich region (called the GS domain) preceding the kinase domain, and a short C-terminal tail. The encoded protein, sometimes termed ALK1, shares similar domain structures with other closely related ALK or activin receptor-like kinase proteins that form a subfamily of receptor serine/threonine kinases. Mutations in this gene are associated with hemorrhagic telangiectasia type 2, also known as Rendu-Osler-Weber syndrome 2. [provided by RefSeq, Jul 2008]

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), ACVRL1. . Gene score misZ 2.4458 (greater than the threshold 3.09). Trascript score misZ 3.182 (greater than threshold 3.09). GenCC has associacion of gene with hereditary hemorrhagic telangiectasia, telangiectasia, hereditary hemorrhagic, type 2.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.917
• PP5: Variant 12-51915407-G-C is Pathogenic according to our data. Variant chr12-51915407-G-C is described in ClinVar as [Pathogenic]. Clinvar id is 426022.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
ACVRL1	NM_000020.3	c.955G>C	p.Gly319Arg	missense_variant	7/10	ENST00000388922.9	NP_000011.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ACVRL1	ENST00000388922.9	c.955G>C	p.Gly319Arg	missense_variant	7/10	1	NM_000020.3	ENSP00000373574	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Telangiectasia, hereditary hemorrhagic, type 2 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 29, 2020

This variant is not present in population databases (ExAC no frequency). This sequence change replaces glycine with arginine at codon 319 of the ACVRL1 protein (p.Gly319Arg). The glycine residue is highly conserved and there is a moderate physicochemical difference between glycine and arginine. This variant has been observed in individual(s) with pulmonary arterial hypertension or hereditary hemorrhagic telangiectasia (PMID: 26387786, 27316748, Invitae). ClinVar contains an entry for this variant (Variation ID: 426022). For these reasons, this variant has been classified as Pathogenic. This variant has been reported to affect ACVRL1 protein function (PMID: 27316748). -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Aug 29, 2017

The ACVRL1 c.955G>C; p.Gly319Arg variant (rs1085307414) has been reported in the literature in individuals with pulmonary arterial hypertension (PAH) and hereditary hemorrhagic telangiectasia (HHT) (Machado 2015, Piao 2016). Functional studies show the variant protein has decreased Smad 1/5 phosphorylation, and reduced activity in a luciferase reporter assay (Piao 2016). Additionally, a different variant at this codon (p.Gly319Asp) has been reported in two individuals with HHT (Lesca 2006). The p.Gly319Arg variant is listed in the ClinVar database (Variation ID: 426022), but is absent from general population databases (Exome Variant Server, Genome Aggregation Database). The glycine at codon 319 is a highly conserved residue in the protein kinase domain, and computational algorithms (SIFT, PolyPhen2, MutationTaster) predict this variant to be damaging to the protein. Taken together, the p.Gly319Arg variant is considered pathogenic. REFERENCES Lesca G et al. Distribution of ENG and ACVRL1 (ALK1) mutations in French HHT patients. Hum Mutat. 2006 Jun;27(6):598. Machado RD et al. Pulmonary Arterial Hypertension: A Current Perspective on Established and Emerging Molecular Genetic Defects. Hum Mutat. 2015 Dec;36(12):1113-27. Piao C et al. Identification of multiple ACVRL1 mutations in patients with pulmonary arterial hypertension by targeted exome capture. Clin Sci (Lond). 2016 Sep 1;130(17):1559-69. -

Pulmonary hypertension, primary, 1 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

Rare Disease Genomics Group, St George's University of London

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.42
CADD	Pathogenic	31
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.89	D;.;D
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Uncertain	0.97	D;D;D
M_CAP	Pathogenic	0.78	D
MetaRNN	Pathogenic	0.92	D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.2	M;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.84	D
PROVEAN	Pathogenic	-7.3	D;D;D
REVEL	Pathogenic	0.83
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0010	D;D;D
Polyphen		1.0	D;.;D
Vest4		0.61
MutPred		0.73		Gain of solvent accessibility (P = 0.0037);.;.;
MVP		0.98
MPC		1.7
ClinPred		1.0	D
GERP RS		5.1
Varity_R		0.94
gMVP		0.93

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs1085307414; hg19: chr12-52309191;