rs1555152468

Positions:

• chr12-51913185-T-C
• chr12-51913185-T-G

Variant summary

Our verdict is Pathogenic. Variant got 15 ACMG points: 15P and 0B. PM1 PM2 PM5 PP2 PP5_Very_Strong

The NM_000020.3(ACVRL1):​c.148T>C​(p.Trp50Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. W50G) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: ACVRL1 NM_000020.3 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 0.604

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 15 ACMG points.

• PM1: In a disulfide_bond (size 23) in uniprot entity ACVL1_HUMAN there are 9 pathogenic changes around while only 1 benign (90%) 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 chrnull-null-null-null is described in UniProt as null.
• 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.
• PP5: Variant 12-51913185-T-C is Pathogenic according to our data. Variant chr12-51913185-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 464760.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ACVRL1	NM_000020.3	c.148T>C	p.Trp50Arg	missense_variant	3/10	ENST00000388922.9	NP_000011.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ACVRL1	ENST00000388922.9	c.148T>C	p.Trp50Arg	missense_variant	3/10	1	NM_000020.3	ENSP00000373574.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1445908 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 717938

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: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary hemorrhagic telangiectasia;C1838163:Telangiectasia, hereditary hemorrhagic, type 2 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Department of Human Genetics, Hannover Medical School

Jan 20, 2023

- -

Telangiectasia, hereditary hemorrhagic, type 2 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 11, 2019

This variant disrupts the p.Trp50 amino acid residue in ACVRL1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9245985, 12843319, 10187774, 14684682, Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C15"). This variant has been observed to segregate with clinical features of hereditary hemorrhagic telangiectasia in a family (Invitae). ClinVar contains an entry for this variant (Variation ID: 464760). This variant is not present in population databases (ExAC no frequency). This sequence change replaces tryptophan with arginine at codon 50 of the ACVRL1 protein (p.Trp50Arg). The tryptophan residue is highly conserved and there is a moderate physicochemical difference between tryptophan and arginine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.61
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.35
CADD	Benign	21
DANN	Benign	0.92
DEOGEN2	Benign	0.19	.;T;.;.
Eigen	Benign	-0.14
Eigen_PC	Benign	0.040
FATHMM_MKL	Benign	0.37	N
LIST_S2	Benign	0.66	T;T;T;T
M_CAP	Pathogenic	0.34	D
MetaRNN	Uncertain	0.64	D;D;D;D
MetaSVM	Uncertain	0.17	D
MutationAssessor	Benign	1.7	.;L;.;.
PrimateAI	Uncertain	0.61	T
PROVEAN	Pathogenic	-11	D;N;N;N
REVEL	Uncertain	0.54
Sift	Pathogenic	0.0	D;T;D;T
Sift4G	Pathogenic	0.0	D;T;D;T
Polyphen		0.0020	.;B;.;.
Vest4		0.61, 0.67
MutPred		0.69		Loss of sheet (P = 0.0084);Loss of sheet (P = 0.0084);.;.;
MVP		0.96
MPC		1.7
ClinPred		1.0	D
GERP RS		5.8
Varity_R		0.55
gMVP		0.95

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: rs1555152468; hg19: chr12-52306969;