rs794728319

Variant names:

• chr15-48427730-CAT-C
• rs794728319
• NM_000138.5:c.7039_7040delAT

Variant summary

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

The NM_000138.5(FBN1):​c.7039_7040delAT​(p.Met2347ValfsTer19) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: FBN1 NM_000138.5 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:18
• Conservation: PhyloP100: 7.18

Genes affected

FBN1 (HGNC:3603): (fibrillin 1) This gene encodes a member of the fibrillin family of proteins. The encoded preproprotein is proteolytically processed to generate two proteins including the extracellular matrix component fibrillin-1 and the protein hormone asprosin. Fibrillin-1 is an extracellular matrix glycoprotein that serves as a structural component of calcium-binding microfibrils. These microfibrils provide force-bearing structural support in elastic and nonelastic connective tissue throughout the body. Asprosin, secreted by white adipose tissue, has been shown to regulate glucose homeostasis. Mutations in this gene are associated with Marfan syndrome and the related MASS phenotype, as well as ectopia lentis syndrome, Weill-Marchesani syndrome, Shprintzen-Goldberg syndrome and neonatal progeroid syndrome. [provided by RefSeq, Apr 2016]

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 15-48427730-CAT-C is Pathogenic according to our data. Variant chr15-48427730-CAT-C is described in ClinVar as [Pathogenic]. Clinvar id is 200171.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr15-48427730-CAT-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FBN1	NM_000138.5	c.7039_7040delAT	p.Met2347ValfsTer19	frameshift_variant	Exon 58 of 66	ENST00000316623.10	NP_000129.3
FBN1	NM_001406716.1	c.7039_7040delAT	p.Met2347ValfsTer19	frameshift_variant	Exon 57 of 65		NP_001393645.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FBN1	ENST00000316623.10	c.7039_7040delAT	p.Met2347ValfsTer19	frameshift_variant	Exon 58 of 66	1	NM_000138.5	ENSP00000325527.5

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:18

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Marfan syndrome Pathogenic:8

Dec 20, 2021

Institute of Human Genetics, University Hospital Muenster

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ACMG categories: PVS1,PP3,PP5 -

Mar 01, 2021

Centre of Medical Genetics, University of Antwerp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

PM2, PVS1, PP4 or PM2, PVS1, PP1, PP4 -

Jan 04, 2018

Laboratory of Medical Genetics, National & Kapodistrian University of Athens

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PVS1, PM2, PP5 -

Nov 07, 2017

Center for Medical Genetics Ghent, University of Ghent

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Nov 07, 2017

Center for Medical Genetics Ghent, University of Ghent

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Nov 01, 2016

Center for Human Genetics, Inc, Center for Human Genetics, Inc

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

-

Lifecell International Pvt. Ltd

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

A Heterozygous Frameshift variant c.7039_7040delAT in Exon 58 of the FBN1 gene that results in the amino acid substitution p.Met2347fs*19 was identified. The observed variant novel in gnomAD exomes and genomes, respectively. The severity of the impact of this variant on the protein is high, based on the effect of the protein and REVEL score . Rare Exome Variant Ensemble Learner (REVEL) is an ensembl method for predicting the pathogenicity of missense variants based on a combination of scores from 13 individual tools: MutPred, FATHMM v2.3, VEST 3.0, PolyPhen-2, SIFT, PROVEAN, MutationAssessor, MutationTaster, LRT, GERP++, SiPhy, phyloP, and phastCons. The REVEL score for an individual missense variant can range from 0 to 1, with higher scores reflecting greater likelihood that the variant is disease-causing. ClinVar has also classified this variant as Pathogenic (variant ID: 200171). This variant has previously been reported for Marfan syndrome (Comeglio P et al., 2007). Based on the above evidence this variant has been classified as Pathogenic according to the ACMG guidelines. -

Aug 21, 2015

Blueprint Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Familial thoracic aortic aneurysm and aortic dissection Pathogenic:3

-

Centre for Genomic and Experimental Medicine, University of Edinburgh

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: research

- -

May 14, 2020

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jul 07, 2022

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.7039_7040delAT pathogenic mutation, located in coding exon 57 of the FBN1 gene, results from a deletion of two nucleotides at nucleotide positions 7039 to 7040, causing a translational frameshift with a predicted alternate stop codon (p.M2347Vfs*19). This alteration has been described in multiple individuals with Marfan syndrome or related phenotypes (Körkkö J et al. J Med Genet. 2002 ;39:34-41; Howarth R et al. Genet Test. 2007;11:146-52; Comeglio P et al. Hum Mutat. 2007;28:928; Attanasio M et al. Clin Genet. 2008 ;74:39-46; Magyar I et al. Hum Mutat. 2009;30:1355-64; Yoo EH et al. Clin Genet. 2010;77:177-82; Regalado ES et al. Clin Genet. 2016 ;89:719-23; Guo J et al. Sci Rep. 2015;5:13115; Somers AE et al. Am J Med Genet A. 2016;170:1786-90). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). In addition, 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. -

not provided Pathogenic:3

Apr 29, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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: 29357934, 11826022, 25101912, 27112580, 17627385, 19863550, 26272055, 17657824, 19618372, 18435798, 29543232, 33436942, 32679894, 34008892, 26621581) -

Sep 23, 2020

Laboratoire Génétique Moléculaire, CHRU TOURS

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Sep 16, 2017

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Weill-Marchesani syndrome 2, dominant Pathogenic:1

Oct 02, 2021

3billion

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Frameshift: predicted to result in a loss or disruption of normal protein function through nonsense-mediated decay (NMD) or protein truncation. Multiple pathogenic variants are reported downstream of the variant (PVS1_VS). The variant was observed as assumed (i.e. paternity and maternity not confirmed) de novoo (3billion dataset, PM6). It is not observed in the gnomAD v2.1.1 dataset (PM2). The variant has been reported multiple times as an established pathogenic variant (ClinVar ID: VCV000200171.11). Therefore, this variant is classified as pathogenic according to the recommendation of ACMG/AMP guideline. -

Acute aortic dissection;C0345050:Congenital aneurysm of ascending aorta Pathogenic:1

Jan 20, 2016

University of Washington Center for Mendelian Genomics, University of Washington

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: research

- -

Marfan Syndrome/Loeys-Dietz Syndrome/Familial Thoracic Aortic Aneurysms and Dissections Pathogenic:1

Feb 25, 2019

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: FBN1 c.7039_7040delAT (p.Met2347ValfsX19) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant was absent in 245612 control chromosomes (gnomAD). c.7039_7040delAT has been reported in the literature in multiple individuals affected with Marfan Syndrome (Korkko_2002, Attanasio_2008, Comeglio_2007, Yoo_2010, Baudhuin_2015). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Eight ClinVar submissions from clinical diagnostic laboratories (evaluation after 2014) cite the variant as likely pathogenic/pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Marfan syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection Pathogenic:1

Aug 31, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Met2347Valfs*19) in the FBN1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in FBN1 are known to be pathogenic (PMID: 17657824, 19293843). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individuals with Marfan syndrome (PMID: 11826022, 17627385, 19618372, 26272055, 26621581). ClinVar contains an entry for this variant (Variation ID: 200171). For these reasons, this variant has been classified as Pathogenic. -

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: rs794728319; hg19: chr15-48719927;