chr15-48488379-C-G

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 4P and 4B. PM1PP2PP3BS2

The NM_000138.5(FBN1):c.3197G>C(p.Arg1066Thr) variant causes a missense change. The variant allele was found at a frequency of 0.000183 in 1,614,134 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00020 ( 1 hom. )

Consequence

FBN1
NM_000138.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:9

Conservation

PhyloP100: 6.17

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 Uncertain_significance. Variant got 0 ACMG points.

PM1

In a domain EGF-like 15; calcium-binding (size 41) in uniprot entity FBN1_HUMAN there are 17 pathogenic changes around while only 0 benign (100%) in NM_000138.5

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, 0.805

BS2

High AC in GnomAd4 at 9 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FBN1	NM_000138.5 link	c.3197G>C	p.Arg1066Thr	missense_variant	Exon 26 of 66	ENST00000316623.10	NP_000129.3	P35555
FBN1	NM_001406716.1 link	c.3197G>C	p.Arg1066Thr	missense_variant	Exon 25 of 65		NP_001393645.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FBN1	ENST00000316623.10 link	c.3197G>C	p.Arg1066Thr	missense_variant	Exon 26 of 66	1	NM_000138.5	ENSP00000325527.5		P35555

Frequencies

GnomAD3 genomes

AF:

0.0000591

AC:

AN:

152244

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000482

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:

0.000103

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000398

AC:

AN:

251492

Hom.:

AF XY:

0.0000441

AC XY:

AN XY:

135920

show subpopulations

Gnomad AFR exome

AF:

0.0000615

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:

0.0000791

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000196

AC:

287

AN:

1461890

Hom.:

Cov.:

AF XY:

0.000183

AC XY:

133

AN XY:

727246

show subpopulations

Gnomad4 AFR exome

AF:

0.0000896

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:

0.000253

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000591

AC:

AN:

152244

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74386

show subpopulations

Gnomad4 AFR

AF:

0.0000482

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:

0.000103

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000847

Hom.:

Bravo

AF:

0.0000567

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000247

AC:

EpiCase

AF:

0.000164

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:9

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:2

May 15, 2023

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

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: FBN1 c.3197G>C (p.Arg1066Thr) results in a non-conservative amino acid change located in the EGF like domain of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-05 in 251492 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in FBN1 causing Marfan Syndrome (4e-05 vs 0.00011), allowing no conclusion about variant significance. c.3197G>C has been reported in the literature in an individual affected with FBN1-related disease (example: Baudhuin_2015). These report(s) do not provide unequivocal conclusions about association of the variant with Marfan Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 25652356, 32123317). Six clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and all classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Feb 19, 2019

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The FBN1 c.3197G>C; p.Arg1066Thr variant (rs376659156), to our knowledge, is not described in the medical literature but contains an entry in ClinVar (Variation ID: 263470). It is observed in the general population at an overall frequency of 0.0039% (11/282908 alleles) in the Genome Aggregation Database. The arginine at codon 1066 is highly conserved, but computational algorithms (PolyPhen-2: possibly damaging, SIFT: tolerated) are inconclusive on the effect of this variant on protein structure/function. Due to the lack of clinical and functional data regarding this variant, its clinical significance cannot be determined with certainty. -

Familial thoracic aortic aneurysm and aortic dissection

Uncertain:2

May 17, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces arginine with threonine at codon 1066 of the FBN1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in one individual suspected of having Marfan syndrome (PMID: 25652356). This variant has been identified in 11/282908 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Apr 28, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R1066T variant (also known as c.3197G>C), located in coding exon 25 of the FBN1 gene, results from a G to C substitution at nucleotide position 3197. The arginine at codon 1066 is replaced by threonine, an amino acid with similar properties. In a study of FBN1 clinical genetic testing among consecutive patients referred for Marfan syndrome, this alteration was reported in one patient with skeletal features (Baudhuin LM et al. J Hum Genet. 2015;60(5):241-52). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Marfan syndrome

Uncertain:1

Sep 23, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

not provided

Uncertain:1

Apr 02, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported as a variant of uncertain significance in patients with Marfan syndrome or an FBN1-related phenotype in published literature (PMID: 25652356, 32123317); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Although located in a calcium-binding EGF-like domain of the FBN1 gene, it does not affect a cysteine residue within this domain; cysteine substitutions in the calcium-binding EGF-like domains represent the majority of pathogenic missense changes associated with FBN1-related disorders (PMID: 12938084); This variant is associated with the following publications: (PMID: 32123317, 34663891, 12938084, 25652356) -

FBN1-related disorder

Uncertain:1

Mar 26, 2024

PreventionGenetics, part of Exact Sciences

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

The FBN1 c.3197G>C variant is predicted to result in the amino acid substitution p.Arg1066Thr. This variant was reported in an individual suspected of Marfan syndrome and referred for FBN1 testing (Baudhuin et al. 2015. PubMed ID: 25652356). Blood RNA analysis showed that this variant does not affect normal splicing (Table S1, Wai et al. 2020. PubMed ID: 32123317). This variant is reported in 0.0077% of alleles in individuals of European (Non-Finnish) descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

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

Uncertain:1

Dec 12, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with threonine, which is neutral and polar, at codon 1066 of the FBN1 protein (p.Arg1066Thr). This variant is present in population databases (rs376659156, gnomAD 0.008%). This missense change has been observed in individual(s) with FBN1-related disease (PMID: 25652356). ClinVar contains an entry for this variant (Variation ID: 263470). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt FBN1 protein function with a positive predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Marfan syndrome;C0265287:Acromicric dysplasia;C1858556:MASS syndrome;C1861456:Stiff skin syndrome;C1869115:Weill-Marchesani syndrome 2, dominant;C3280054:Geleophysic dysplasia 2;C3541518:Ectopia lentis 1, isolated, autosomal dominant;C4310796:Progeroid and marfanoid aspect-lipodystrophy syndrome

Uncertain:1

Apr 26, 2022

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.63

BayesDel_addAF

Uncertain

0.13

BayesDel_noAF

Uncertain

0.13

CADD

Uncertain

DANN

Uncertain

0.97

Eigen

Uncertain

0.66

Eigen_PC

Pathogenic

0.72

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.94

M_CAP

Uncertain

0.19

MetaRNN

Pathogenic

0.80

MetaSVM

Uncertain

0.40

PrimateAI

Pathogenic

0.87

PROVEAN

Uncertain

-3.5

REVEL

Uncertain

0.60

Sift

Benign

0.072

Sift4G

Benign

0.46

Vest4

0.85

MVP

0.82

MPC

1.1

ClinPred

0.24

GERP RS

6.2

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