rs1318118188

chr12-51913243-G-Achr12-51913243-G-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.206G>A(p.Cys69Tyr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000695 in 1,438,966 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. C69F) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: ACVRL1 NM_000020.3 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 3.57

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 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 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 chr12-51913243-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 533353.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, 0.991
• PP5: Variant 12-51913243-G-A is Pathogenic according to our data. Variant chr12-51913243-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 935121.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.206G>A	p.Cys69Tyr	missense_variant	3/10	ENST00000388922.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ACVRL1	ENST00000388922.9	c.206G>A	p.Cys69Tyr	missense_variant	3/10	1	NM_000020.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.95e-7 AC: 1 AN: 1438966 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 713670

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: 0.00

Gnomad4 OTH exome AF: 0.0000168

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Telangiectasia, hereditary hemorrhagic, type 2 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Apr 22, 2022

This sequence change replaces cysteine, which is neutral and slightly polar, with tyrosine, which is neutral and polar, at codon 69 of the ACVRL1 protein (p.Cys69Tyr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with hereditary hemorrhagic telangiectasia (PMID: 16705692; Invitae). ClinVar contains an entry for this variant (Variation ID: 935121). 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. This variant affects a cysteine residue located within the ACVRL1 protein ectodomain. Cysteine residues in this domain of ACVRL1 are involved in the formation of disulfide bridges critical for protein structure and stability (PMID: 22028876, 22718755, 22799562). In addition, missense substitutions within the ACVRL1 ectodomain affecting cysteine residues are overrepresented in patients with HHT (PMID: 20501893, 26176610 and www.hhtmutation.org). This variant disrupts the p.Cys69 amino acid residue in ACVRL1. Other variant(s) that disrupt this residue have been observed in individuals with ACVRL1-related conditions (PMID: 16525724, 21158752), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.49
Cadd	Pathogenic	26
Dann	Uncertain	0.99
Eigen	Uncertain	0.62
Eigen_PC	Uncertain	0.57
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Benign	0.78	T;T;T;T
M_CAP	Pathogenic	0.89	D
MetaRNN	Pathogenic	0.99	D;D;D;D
MetaSVM	Pathogenic	0.88	D
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.49	T
PROVEAN	Pathogenic	-9.1	D;D;N;D
Sift	Pathogenic	0.0	D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		1.0	.;D;.;.
Vest4		0.83, 0.94
MutPred		0.99		Gain of phosphorylation at C69 (P = 0.0516);Gain of phosphorylation at C69 (P = 0.0516);.;.;
MVP		1.0
MPC		2.0
ClinPred		1.0	D
GERP RS		5.2
Varity_R		0.93
gMVP		1.0

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: rs1318118188; hg19: chr12-52307027;