rs1085307421

chr12-51919062-G-Achr12-51919062-G-C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5

The NM_000020.3(ACVRL1):c.1324G>A(p.Val442Met) 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V442A) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: ACVRL1 NM_000020.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: 10.0

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 12 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, 1 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 chr12-51919063-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 1066980.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP2: Missense variant where missense usually causes diseases, ACVRL1
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.952
• PP5: Variant 12-51919062-G-A is Pathogenic according to our data. Variant chr12-51919062-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 426030.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ACVRL1	NM_000020.3	c.1324G>A	p.Val442Met	missense_variant	9/10	ENST00000388922.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ACVRL1	ENST00000388922.9	c.1324G>A	p.Val442Met	missense_variant	9/10	1	NM_000020.3	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Pulmonary arterial hypertension related to hereditary hemorrhagic telangiectasia Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

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

-

- -

Telangiectasia, hereditary hemorrhagic, type 2 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Nov 29, 2023

This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 442 of the ACVRL1 protein (p.Val442Met). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with hereditary hemorrhagic telangiectasia and/or pulmonary hypertension (PMID: 20056902; Invitae). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 426030). 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%. This variant disrupts the p.Val442 amino acid residue in ACVRL1. Other variant(s) that disrupt this residue have been observed in individuals with ACVRL1-related conditions (PMID: 18498373), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Nov 14, 2019

Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 20056902) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.90
BayesDel_addAF	Pathogenic	0.37	D
BayesDel_noAF	Pathogenic	0.29
Cadd	Pathogenic	33
Dann	Pathogenic	1.0
DEOGEN2	Pathogenic	0.91	D;.;D
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.90
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Pathogenic	0.32	D
MetaRNN	Pathogenic	0.95	D;D;D
MetaSVM	Uncertain	0.20	D
MutationAssessor	Uncertain	2.4	M;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.74	T
PROVEAN	Uncertain	-2.7	D;D;D
REVEL	Uncertain	0.60
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0010	D;D;D
Polyphen		1.0	D;.;D
Vest4		0.78
MutPred		0.97		Gain of ubiquitination at K440 (P = 0.0597);.;.;
MVP		0.92
MPC		1.5
ClinPred		0.99	D
GERP RS		5.0
Varity_R		0.92
gMVP		0.80

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.17		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: rs1085307421; hg19: chr12-52312846;