rs1206813753

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 15 ACMG points: 15P and 0B. PM2PP2PP3_StrongPP5_Very_Strong

The NM_000138.5(FBN1):c.2977T>C(p.Cys993Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,126 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 11/18 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)

Consequence

FBN1
NM_000138.5 missense

Scores

Clinical Significance

Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 9.32

Variant links:

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]

FBN1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 15 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP2

Missense variant in the FBN1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 1311 curated pathogenic missense variants (we use a threshold of 10). The gene has 112 curated benign missense variants. Gene score misZ: 5.0644 (above the threshold of 3.09). Trascript score misZ: 8.1787 (above the threshold of 3.09). GenCC associations: The gene is linked to MASS syndrome, Weill-Marchesani syndrome, geleophysic dysplasia, Shprintzen-Goldberg syndrome, Acromicric dysplasia, familial thoracic aortic aneurysm and aortic dissection, progeroid and marfanoid aspect-lipodystrophy syndrome, ectopia lentis 1, isolated, autosomal dominant, Marfan syndrome, Weill-Marchesani syndrome 2, dominant, isolated ectopia lentis, neonatal Marfan syndrome, stiff skin syndrome.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.996

PP5

Variant 15-48489956-A-G is Pathogenic according to our data. Variant chr15-48489956-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 527187.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FBN1	NM_000138.5 link	c.2977T>C	p.Cys993Arg	missense_variant	Exon 25 of 66	ENST00000316623.10	NP_000129.3	P35555
FBN1	NM_001406716.1 link	c.2977T>C	p.Cys993Arg	missense_variant	Exon 24 of 65		NP_001393645.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FBN1	ENST00000316623.10 link	c.2977T>C	p.Cys993Arg	missense_variant	Exon 25 of 66	1	NM_000138.5	ENSP00000325527.5		P35555

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152126

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

Cov.:

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152126

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74324

show subpopulations

Gnomad4 AFR

AF:

0.00

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:2

Nov 16, 2017

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Sep 26, 2024

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Affects a cysteine residue within a TGF-binding protein domain (aka TB domain or 8-Cysteine domain) and is expected to disrupt disulfide bonding within this domain; other missense substitutions that affect cysteine residues within this TGF-binding protein domain have been reported in association with various FBN1-related phenotypes, including Marfan syndrome (HGMD); Has not been previously published as pathogenic or benign to our knowledge; Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function -

Marfan syndrome

Pathogenic:1

Apr 24, 2023

All of Us Research Program, National Institutes of Health

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces cysteine with arginine at codon 993 in the transforming growth factor beta--binding protein-like (TB) motif 5 of the FBN1 protein. About 90% of variants altering cysteine residues in the TB domains of the FBN1 gene are associated with disease (PMID: 31227806). Computational prediction also suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). This variant has been observed in two individuals affected with FBN1-related disorders (communication with an external laboratory; ClinVar SCV000753077.4). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Based on the available evidence, this variant is classified as Likely Pathogenic. -

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

Pathogenic:1

Aug 29, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, this variant is a novel missense change affecting a residue crucial for protein stability and function. Although additional genetic data will be necessary to further confirm pathogenicity for this variant, cysteine substitutions located in FBN1 TGFBP domains are likely deleterious. For these reasons, this variant has been classified as Likely Pathogenic. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). This variant affects a cysteine residue located within a TGFBP domain of the FBN1 protein. Cysteine residues in these domains are believed to be involved in intramolecular disulfide bridges and to be important for FBN1 structure. Although the exact function of the FBN1 TGFBP domains has not being elucidated (PMID: 10930463, 27437668), missense substitutions within the TGFBP domains affecting cysteine residues are significantly overrepresented among patients with Marfan syndrome (PMID: 16571647, 17701892). This variant has not been reported in the literature in individuals with FBN1-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces cysteine with arginine at codon 993 of the FBN1 protein (p.Cys993Arg). The cysteine residue is highly conserved and there is a large physicochemical difference between cysteine and arginine. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.99

BayesDel_addAF

Pathogenic

0.58

BayesDel_noAF

Pathogenic

0.59

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Pathogenic

0.91

Eigen_PC

Pathogenic

0.86

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.87

M_CAP

Pathogenic

0.85

MetaRNN

Pathogenic

1.0

MetaSVM

Pathogenic

1.1

PrimateAI

Pathogenic

0.84

PROVEAN

Pathogenic

-10

REVEL

Pathogenic

0.96

Sift

Uncertain

0.0010

Sift4G

Pathogenic

0.0010

Vest4

0.99

MutPred

0.99

Gain of phosphorylation at T990 (P = 0.0923);

MVP

0.99

MPC

0.89

ClinPred

1.0

GERP RS

5.7

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over