12-51913648-CTGGG-C

Position:

• chr12-51913648-CTGGG-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000020.3(ACVRL1):​c.406_409del​(p.Gly136SerfsTer28) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,607,206 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: ACVRL1 NM_000020.3 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 2.94

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 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 12-51913648-CTGGG-C is Pathogenic according to our data. Variant chr12-51913648-CTGGG-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 212806.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.406_409del	p.Gly136SerfsTer28	frameshift_variant	4/10	ENST00000388922.9	NP_000011.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ACVRL1	ENST00000388922.9	c.406_409del	p.Gly136SerfsTer28	frameshift_variant	4/10	1	NM_000020.3	ENSP00000373574	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152250 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000822 AC: 2 AN: 243456 Hom.: 0 AF XY: 0.00000754 AC XY: 1 AN XY: 132630

Gnomad AFR exome AF: 0.000126

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.87e-7 AC: 1 AN: 1454956 Hom.: 0 AF XY: 0.00000138 AC XY: 1 AN XY: 724208

Gnomad4 AFR exome AF: 0.0000299

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 AF: 0.00000657 AC: 1 AN: 152250 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74372

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000113

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Telangiectasia, hereditary hemorrhagic, type 2 Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 22, 2024	This sequence change creates a premature translational stop signal (p.Gly136Serfs*28) in the ACVRL1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in ACVRL1 are known to be pathogenic (PMID: 15879500). This variant is present in population databases (rs750662466, gnomAD 0.01%). This premature translational stop signal has been observed in individuals with hereditary hemorrhagic telangiectasia (HHT) (PMID: 10694922, 15879500). This variant is also known as p.G136fs. ClinVar contains an entry for this variant (Variation ID: 212806). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Jan 17, 2020	The ACVRL1 c.406_409delGGTG; p.Gly136fs variant (rs863223416) is reported in the literature in an individual with HHT (Klaus 1998), and is reported in the ClinVar database (Variation ID: 212806). This variant is only observed on two alleles in the Genome Aggregation Database, indicating it is not a common polymorphism. This variant causes a frameshift by deleting four nucleotides, so it is predicted to result in a truncated protein or mRNA subject to nonsense-mediated decay. Based on available information, this variant is considered to be pathogenic. REFERENCES Klaus DJ et al. Novel missense and frameshift mutations in the activin receptor-like kinase-1 gene in hereditary hemorrhagic telangiectasia. Mutations in brief no. 164. Online. Hum Mutat. 1998;12(2):137. -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	Sep 08, 2021	PP4, PM1, PVS1 -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Mar 08, 2024	Not observed at significant frequency in large population cohorts (gnomAD); Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 15879500, 10694922) -

ACVRL1-related disorder Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Aug 09, 2023

The ACVRL1 c.406_409delGGTG variant is predicted to result in a frameshift and premature protein termination (p.Gly136Serfs*28). This variant has been reported to be causative for hereditary hemorrhagic telangiectasia (HHT) (Klaus et al. 1997. PubMed ID: 10694922) This variant is reported in 0.013% of alleles in individuals of African descent in gnomAD (http://gnomad.broadinstitute.org/variant/12-52307432-CTGGG-C). Frameshift variants in ACVRL1 are expected to be pathogenic. This variant is interpreted as likely pathogenic. -

Cardiovascular phenotype Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 28, 2023

The c.406_409delGGTG pathogenic mutation, located in coding exon 3 of the ACVRL1 gene, results from a deletion of 4 nucleotides at nucleotide positions 406 to 409, causing a translational frameshift with a predicted alternate stop codon (p.G136Sfs*28). In one study, this variant was seen in an individual with hereditary hemorrhagic telangiectasia (HHT) (Klaus DJ et al. Hum Mutat. 1998:12(2):137). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

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: rs863223416; hg19: chr12-52307432;