NM_000020.3:c.1412G>A

Variant names:

• chr12-51920793-G-A
• rs1555154137
• NM_000020.3:c.1412G>A

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP2 PP3_Strong

The NM_000020.3(ACVRL1):​c.1412G>A​(p.Cys471Tyr) 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. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C471R) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 31)
• Consequence: ACVRL1 NM_000020.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.99
• Publications: 1 publications found

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]

ACVRL1 Gene-Disease associations (from GenCC):

• telangiectasia, hereditary hemorrhagic, type 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), ClinGen, Genomics England PanelApp
• hereditary hemorrhagic telangiectasia

  Inheritance: AR, AD Classification: SUPPORTIVE, LIMITED Submitted by: Ambry Genetics, Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PM1: In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 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 chr12-51920792-T-C is described in ClinVar as Pathogenic. ClinVar VariationId is 2811227.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP2: Missense variant in the ACVRL1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 203 curated pathogenic missense variants (we use a threshold of 10). The gene has 24 curated benign missense variants. Gene score misZ: 2.4458 (below the threshold of 3.09). Trascript score misZ: 3.182 (above the threshold of 3.09). GenCC associations: The gene is linked to telangiectasia, hereditary hemorrhagic, type 2, hereditary hemorrhagic telangiectasia.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.968

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000020.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ACVRL1	NM_000020.3	MANE Select	c.1412G>A	p.Cys471Tyr	missense	Exon 10 of 10	NP_000011.2
	ACVRL1	NM_001077401.2		c.1412G>A	p.Cys471Tyr	missense	Exon 9 of 9	NP_001070869.1
	ACVRL1	NM_001406487.1		c.1412G>A	p.Cys471Tyr	missense	Exon 11 of 11	NP_001393416.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ACVRL1	ENST00000388922.9	TSL:1 MANE Select	c.1412G>A	p.Cys471Tyr	missense	Exon 10 of 10	ENSP00000373574.4
	ACVRL1	ENST00000550683.5	TSL:1	c.1454G>A	p.Cys485Tyr	missense	Exon 9 of 9	ENSP00000447884.1
	ACVRL1	ENST00000551576.6	TSL:1	c.1412G>A	p.Cys471Tyr	missense	Exon 11 of 11	ENSP00000455848.2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Telangiectasia, hereditary hemorrhagic, type 2 Uncertain:1

Apr 25, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces cysteine with tyrosine at codon 471 of the ACVRL1 protein (p.Cys471Tyr). The cysteine residue is highly conserved and there is a large physicochemical difference between cysteine and tyrosine. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a ACVRL1-related disease. 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. In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.61	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.6	H
PhyloP100		10
PrimateAI	Pathogenic	0.81	D
PROVEAN	Pathogenic	-9.9	D
REVEL	Pathogenic	0.90
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.95
MutPred		0.81		Gain of phosphorylation at C471 (P = 0.0438)
MVP		1.0
MPC		2.0
ClinPred		1.0	D
GERP RS		4.4
Varity_R		0.99
gMVP		1.0
Mutation Taster		=2/98	disease causing

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

Other links and lift over

dbSNP: rs1555154137; hg19: chr12-52314577;