rs1060503243

Positions:

• chr12-51920797-G-C
• chr12-51920797-G-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PS1 PM1 PM2 PM5 PP2 PP3_Strong PP5

The NM_000020.3(ACVRL1):​c.1416G>C​(p.Trp472Cys) 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 nucleotide change resulting in same amino acid change has been previously reported as Pathogenicin ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. W472R) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 31)
• Consequence: ACVRL1 NM_000020.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:2
• 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 16 ACMG points.

• PS1: Transcript NM_000020.3 (ACVRL1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar as 652327
• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 4 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 chr12-51920795-T-C is described in Lovd as [Likely_pathogenic].
• 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, 0.967
• PP5: Variant 12-51920797-G-C is Pathogenic according to our data. Variant chr12-51920797-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 411309.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=2, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ACVRL1	NM_000020.3	c.1416G>C	p.Trp472Cys	missense_variant	10/10	ENST00000388922.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ACVRL1	ENST00000388922.9	c.1416G>C	p.Trp472Cys	missense_variant	10/10	1	NM_000020.3	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 31

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Telangiectasia, hereditary hemorrhagic, type 2 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Dec 23, 2021

For these reasons, this variant has been classified as Pathogenic. 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. ClinVar contains an entry for this variant (Variation ID: 411309). This missense change has been observed in individual(s) with hereditary hemorrhagic telangiectasia (Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces tryptophan, which is neutral and slightly polar, with cysteine, which is neutral and slightly polar, at codon 472 of the ACVRL1 protein (p.Trp472Cys). -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Apr 04, 2022

Has not been previously published as pathogenic or benign to our knowledge; Not observed in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 16, 2020

The p.W472C variant (also known as c.1416G>C), located in coding exon 9 of the ACVRL1 gene, results from a G to C substitution at nucleotide position 1416. The tryptophan at codon 472 is replaced by cysteine, an amino acid with highly dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Pathogenic	33
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.92	D;.;D
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D;D;D
M_CAP	Pathogenic	0.40	D
MetaRNN	Pathogenic	0.97	D;D;D
MetaSVM	Uncertain	0.34	D
MutationAssessor	Pathogenic	3.1	M;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.78	T
PROVEAN	Pathogenic	-12	D;D;D
REVEL	Pathogenic	0.68
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		1.0	D;.;D
Vest4		0.94
MutPred		0.81		Gain of disorder (P = 0.0126);.;.;
MVP		0.89
MPC		1.9
ClinPred		1.0	D
GERP RS		4.4
Varity_R		0.96
gMVP		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1060503243; hg19: chr12-52314581;