rs1085307419

Positions:

• chr12-51919008-C-A
• chr12-51919008-C-G
• chr12-51919008-C-T

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Moderate

The NM_000020.3(ACVRL1):​c.1270C>A​(p.Pro424Thr) 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 Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P424R) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: ACVRL1 NM_000020.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 7.91

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.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 6 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 chr12-51919009-C-G is described in ClinVar as [Pathogenic]. Clinvar id is 836149.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• 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, 0.991
• PP5: Variant 12-51919008-C-A is Pathogenic according to our data. Variant chr12-51919008-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 426028.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ACVRL1	NM_000020.3	c.1270C>A	p.Pro424Thr	missense_variant	9/10	ENST00000388922.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ACVRL1	ENST00000388922.9	c.1270C>A	p.Pro424Thr	missense_variant	9/10	1	NM_000020.3	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Telangiectasia, hereditary hemorrhagic, type 2 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 12, 2018

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This sequence change replaces proline with threonine at codon 424 of the ACVRL1 protein (p.Pro424Thr). The proline residue is highly conserved and there is a small physicochemical difference between proline and threonine. This variant is not present in population databases (ExAC no frequency). This variant has been observed in individuals affected with hereditary hemorrhagic telangiectasia (PMID: 9245985) and pulmonary arterial hypertension (PMID: 18159113, Invitae). ClinVar contains an entry for this variant (Variation ID: 426028). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. Variants that disrupt the p.Pro424 amino acid residue in ACVRL1 have been observed in affected individuals (PMID: 9245985, 18159113, 15712271, 22781769). This suggests that it is a clinically significant residue, and that other variants that disrupt this residue are likely to be causative of disease. -

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	0.40	D
BayesDel_noAF	Pathogenic	0.34
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.94	D;.;D
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.89
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	D;D;D
M_CAP	Pathogenic	0.59	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Uncertain	0.52	D
MutationAssessor	Pathogenic	3.0	M;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.57	T
PROVEAN	Pathogenic	-7.7	D;D;D
REVEL	Pathogenic	0.79
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0010	D;D;D
Polyphen		1.0	D;.;D
Vest4		0.79
MutPred		0.98		Gain of phosphorylation at P424 (P = 0.0502);.;.;
MVP		0.96
MPC		1.6
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.97
gMVP		0.93

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: rs1085307419; hg19: chr12-52312792;