12-51916219-G-A

Variant summary

Our verdict is Pathogenic. Variant got 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000020.3(ACVRL1):c.1232G>A(p.Arg411Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,762 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 Pathogenic (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R411W) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: ACVRL1 NM_000020.3 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:14
• Conservation: PhyloP100: 9.99

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 19 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 7 uncertain in NM_000020.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr12-51916218-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 8251.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant where missense usually causes diseases, ACVRL1
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.989
• PP5: Variant 12-51916219-G-A is Pathogenic according to our data. Variant chr12-51916219-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 8243.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr12-51916219-G-A is described in Lovd as [Pathogenic]. Variant chr12-51916219-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ACVRL1	NM_000020.3	c.1232G>A	p.Arg411Gln	missense_variant	8/10	ENST00000388922.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ACVRL1	ENST00000388922.9	c.1232G>A	p.Arg411Gln	missense_variant	8/10	1	NM_000020.3	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000798 AC: 2 AN: 250642 Hom.: 0 AF XY: 0.00000738 AC XY: 1 AN XY: 135552

Gnomad AFR exome AF: 0.0000617

Gnomad AMR exome AF: 0.00

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: 0.000163

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461762 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727164

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:14

Revision: reviewed by expert panel

Submissions by phenotype

Telangiectasia, hereditary hemorrhagic, type 2 Pathogenic:9

Pathogenic, no assertion criteria provided	literature only	OMIM	Apr 01, 2004	- -
Likely pathogenic, criteria provided, single submitter	research	NIHR Bioresource Rare Diseases, University of Cambridge	Jan 01, 2018	PS3+PM2+PP4+PP5 -
Pathogenic, reviewed by expert panel	curation	ClinGen Hereditary Hemorrhagic Telangiectasia Variant Curation Expert Panel, ClinGen	Mar 15, 2024	The NM_000020.3: c.1232G>A variant in ACVRL1 is a missense variant predicted to cause substitution of arginine by glutamine at amino acid 411 (p.Arg411Gln). The overall minor allele frequency in gnomAD v2.1.1 is 0.000007980 (2/250642 alleles), which is lower than the ClinGen Hereditary Hemorrhagic Telangiectasia VCEP threshold (<6 total alleles) for PM2_Supporting, meeting this criterion (PM2_Supporting). This variant has been reported in >10 probands with a phenotype consistent with HHT (PS4; PMID: 8640225, 31400083, 32300199, Internal lab contributors). At least one patient's phenotype meets Curacao Criteria for HHT, and sequencing and large deletion/duplication analysis was performed for ENG and ACVRL1, which is highly specific for HHT (PP4_Moderate; PMID: 32300199). The variant has been reported to segregate with HHT in 8 affected family members from one family (PP1_Strong; PMID: 8640225). The computational predictor REVEL gives a score of 0.904, which is above the threshold of greater than or equal to 0.644, evidence that correlates with impact to ACVRL1 function (PP3). Additionally, binding assays in cell lines showed no BMP9 response indicating that this variant impacts protein function (PS3_Supporting; PMID: 20501893). In summary, this variant meets the criteria to be classified as pathogenic for autosomal dominant hereditary hemorrhagic telangiectasia based on the ACMG/AMP criteria applied, as specified by the ClinGen Hereditary Hemorrhagic Telangiectasia Variant Curation Expert Panel: PS4, PP1_Strong, PP4_Moderate, PM2_Supporting, PP3, PS3_Supporting (specification version 1.0.0; 1/4/2024). -
Pathogenic, no assertion criteria provided	clinical testing	Blueprint Genetics	Oct 06, 2014	- -
Pathogenic, criteria provided, single submitter	clinical testing	Laboratory of Medical Genetics, National & Kapodistrian University of Athens	Nov 20, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Oct 31, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Mar 11, 2020	The ACVRL1 c.1232G>A; p.Arg411Gln variant (rs121909284) has been reported in ClinVar (Variation ID: 8243), and described in the literature in multiple families with hereditary hemorrhagic telangiectasia (HHT) (see HHT database link and references therein). Additionally, this variant has been shown to have defective BMP9 ligand signaling (Ricard 2010). The arginine at codon 411 is a highly conserved residue located in the protein kinase domain, and computational algorithms (SIFT, PolyPhen2, MutationTaster) predict this variant to be damaging to the protein. Taken together, this variant is considered pathogenic. REFERENCES Link to ARUP HHT database: http://arup.utah.edu/database/ACVRL1/ACVRL1_display.php Link to ClinVar for p.Arg411Gln: https://www.ncbi.nlm.nih.gov/clinvar/variation/8243/ Ricard N et al. (2010) Functional analysis of the BMP9 response of ALK1 mutants from HHT2 patients: a diagnostic tool for novel ACVRL1 mutations. Blood. 116(9):1604-12. -
Pathogenic, criteria provided, single submitter	clinical testing	Victorian Clinical Genetics Services, Murdoch Childrens Research Institute	Jun 11, 2020	Based on the classification scheme VCGS_Germline_v1.1.1, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss-of-function is a known mechanism of disease for this gene. (N) 0107 - This gene is known to be associated with autosomal dominant disease. (N) 0200 - Variant is predicted to result in a missense amino acid change from an arginine to a glutamine (exon 8). (N) 0251 - Variant is heterozygous. (N) 0302 - Variant is present in gnomAD <0.001 for a dominant condition (2 heterozygotes, 0 homozygotes). (P) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (P) 0601 - Variant affects at least one well-established (essential) functional domain or motif. This variant at residue 411 was shown to be essential for the function of the kinase domain (PMID: 20501893). (P) 0701 - Comparable variants have very strong previous evidence for pathogenicity. Alternate changes at the same residue, to tryptophan and proline, have previously been reported in multiple patients with HHT (ClinVar, HGMD, LOVD, PMID: 15024723). (P) 0801 - Strong previous evidence of pathogenicity in unrelated individuals. The variant has previously been classified as pathogenic and reported in multiple patients with HHT (ClinVar, HGMD, LOVD, PMID: 8640225, PMID: 31400083). (P) 0901 - Strong evidence for segregation with disease. The variant has been reported to segregate with disease in HHT families (PMID: 8640225, PMID: 31400083). (P) 1002 - Moderate functional evidence supporting abnormal protein function. Functional studies in transfected cells demonstrated that the variant resulted in a reduced ability of ACVRL1 to bind its ligand BMP9 (PMID: 20501893). (P) 1102 - Strong phenotype match. (P) 1208 - Inheritance information for this variant is not currently available. (N) Legend: (P) - Pathogenic, (N) - Neutral, (B) - Benign -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 17, 2024	This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 411 of the ACVRL1 protein (p.Arg411Gln). This variant is present in population databases (rs121909284, gnomAD 0.007%). This missense change has been observed in individuals with hereditary hemorrhagic telangiectasia (HHT) (PMID: 8640225, 15024723, 20414677, 23805858). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 8243). 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 expected to disrupt ACVRL1 protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects ACVRL1 function (PMID: 14684682, 20501893). This variant disrupts the p.Arg411 amino acid residue in ACVRL1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 15024723, 20501893). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Mar 01, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	Feb 28, 2023	PP3, PM1, PM2_supporting, PS3, PS4 -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Feb 24, 2023	Published functional studies demonstrate reduced ACVRL1 activity (Gu et al., 2006; Ricard et al., 2010; Laux et al., 2013); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 17384219, 15521985, 16754821, 25892364, 34872578, 20501893, 11802521, 12700602, 14684682, 18673552, 16540754, 16752392, 16470787, 16429404, 16282348, 23863480, 15611116, 20067780, 28652319, 15024723, 9245985, 15880681, 12114496, 29743074, 31630786, 32503579, 34008892, 32300199, 33201366, 32573726, 8640225) -

Pulmonary arterial hypertension related to hereditary hemorrhagic telangiectasia Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Apr 01, 2004

- -

Cardiovascular phenotype Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 19, 2022

The p.R411Q pathogenic mutation (also known as c.1232G>A), located in coding exon 7 of the ACVRL1 gene, results from a G to A substitution at nucleotide position 1232. The arginine at codon 411 is replaced by glutamine, an amino acid with highly similar properties.This mutation has been detected in multiple individuals with a clinical diagnosis of hereditary hemorrhagic telangiectasia (HHT) (Gedge F et al. J Molec Diag. 2007;9(2):258-265; Tørring PM et al. PLoS ONE, 2014 Mar;9:e90272), including an individual with a history of pulmonary hypertension (Harrison RE et al. J. Med. Genet., 2003 Dec;40:865-71). This amino acid position is located in the intracellular kinase domain, and a functional study found that p.R411Q interferes with downstream signaling activity of the protein (Ricard N et al. Blood. 2010: 116(9):1604-12). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Two additional disease causing alterations have been described at the same codon, p.R411P and p.R411W (Gedge F et al. J Molec Diag. 2007;9(2):258-265; Trembath RC et al. N. Engl. J. Med., 2001 Aug;345:325-34). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.77
BayesDel_addAF	Pathogenic	0.37	D
BayesDel_noAF	Pathogenic	0.48
Cadd	Pathogenic	33
Dann	Pathogenic	1.0
DEOGEN2	Pathogenic	0.91	D;.;D
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Pathogenic	0.69	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.1	M;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.59	T
PROVEAN	Uncertain	-3.7	D;D;D
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0010	D;D;D
Sift4G	Uncertain	0.0020	D;D;D
Polyphen		1.0	D;.;D
Vest4		0.90
MutPred		0.96		Loss of MoRF binding (P = 0.0867);.;.;
MVP		0.97
MPC		1.7
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.97
gMVP		0.92

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: rs121909284; hg19: chr12-52310003; COSMIC: COSV66359807; COSMIC: COSV66359807;