chr15-48644711-T-C

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received -5 ACMG points: 0P and 5B. BP2BS1

This summary comes from the ClinGen Evidence Repository: The NM_000138 c.59A>G, is a missense variant in FBN1 predicted to cause a substitution of a Tyrosine by a Cysteine at amino acid 20 (p.Tyr20Cys). This variant was found in a proband with aortic root dilatation and a systemic score of 7 or above which is a highly specific phenotype for Marfan syndrome, however, a pathogenic splice variant in FBN1 was also identified in cis in this individual (BP2). The variant segregates with the disease in 4 affected family members, who also carry the pathogenic splice variant in FBN1. The variant in FBN1 has been reported 12 times in ClinVar: 3 times as likely benign, 8 times as uncertain significance and once as likely pathogenic (Variation ID: 161245). This variant has been identified in 37 individuals of European non-Finnish origin (MAF: 0.029%) (BS1; https://gnomad.broadinstitute.org/ version 2.1.1). The constraint z-score for missense variants affecting FBN1 is 5.06, however due to the presence of two benign arguments, PP2 cannot be used. In summary, this variant meets criteria to be classified as likely benign for Marfan syndrome based on the ACMG/AMP criteria applied, as specified by the ClinGen FBN1 VCEP: BS1, BP2 LINK:https://erepo.genome.network/evrepo/ui/classification/CA016208/MONDO:0007947/022

Frequency

Genomes: 𝑓 0.00016 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00026 ( 0 hom. )

Consequence

FBN1
NM_000138.5 missense

Scores

Clinical Significance

Uncertain significance reviewed by expert panel P:1U:9B:4O:1

Conservation

PhyloP100: 3.86

Publications

10 publications found

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 Gene-Disease associations (from GenCC):

familial thoracic aortic aneurysm and aortic dissection
Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
Marfan syndrome
Inheritance: AD, AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, ClinGen, G2P, PanelApp Australia, Orphanet, Ambry Genetics
Acromicric dysplasia
Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics
progeroid and marfanoid aspect-lipodystrophy syndrome
Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Orphanet
stiff skin syndrome
Inheritance: AD Classification: STRONG, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
Weill-Marchesani syndrome 2, dominant
Inheritance: AD Classification: STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
geleophysic dysplasia
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
isolated ectopia lentis
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
neonatal Marfan syndrome
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
Weill-Marchesani syndrome
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
ectopia lentis 1, isolated, autosomal dominant
Inheritance: AD Classification: LIMITED Submitted by: G2P
Shprintzen-Goldberg syndrome
Inheritance: AD, Unknown Classification: LIMITED, NO_KNOWN Submitted by: ClinGen, Labcorp Genetics (formerly Invitae)

FBN1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received -5 ACMG points.

BP2

For more information check the summary or visit ClinGen Evidence Repository.

BS1

For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FBN1	NM_000138.5 link	c.59A>G	p.Tyr20Cys	missense_variant	Exon 2 of 66	ENST00000316623.10	NP_000129.3	P35555
FBN1	NM_001406716.1 link	c.59A>G	p.Tyr20Cys	missense_variant	Exon 1 of 65		NP_001393645.1
FBN1	NM_001406717.1 link	c.59A>G	p.Tyr20Cys	missense_variant	Exon 2 of 9		NP_001393646.1
FBN1	NM_001406718.1 link	c.59A>G	p.Tyr20Cys	missense_variant	Exon 2 of 3		NP_001393647.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FBN1	ENST00000316623.10 link	c.59A>G	p.Tyr20Cys	missense_variant	Exon 2 of 66	1	NM_000138.5	ENSP00000325527.5		P35555

Frequencies

GnomAD3 genomes

AF:

0.000164

AC:

AN:

152152

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.0000942

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000147

AC:

AN:

251386

AF XY:

0.000103

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000463

Gnomad NFE exome

AF:

0.000299

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000256

AC:

374

AN:

1461816

Hom.:

Cov.:

AF XY:

0.000231

AC XY:

168

AN XY:

727210

show subpopulations

African (AFR)

AF:

0.0000597

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39696

South Asian (SAS)

AF:

0.0000812

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.0000187

AC:

AN:

53352

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.000316

AC:

351

AN:

1112010

Other (OTH)

AF:

0.000199

AC:

AN:

60392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

112

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

100

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.000164

AC:

AN:

152270

Hom.:

Cov.:

AF XY:

0.000161

AC XY:

AN XY:

74448

show subpopulations

African (AFR)

AF:

0.0000722

AC:

AN:

41576

American (AMR)

AF:

0.00

AC:

AN:

15306

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5154

South Asian (SAS)

AF:

0.000207

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.0000942

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000294

AC:

AN:

67998

Other (OTH)

AF:

0.00

AC:

AN:

2108

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.519

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000119

Hom.:

Bravo

AF:

0.000132

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000349

AC:

ExAC

AF:

0.000148

AC:

EpiCase

AF:

0.000218

EpiControl

AF:

0.000237

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1Uncertain:9Benign:4Other:1

Revision: reviewed by expert panel

LINK: link

Submissions by phenotype

not provided

Uncertain:5Other:1

May 01, 2016

CeGaT Center for Human Genetics Tuebingen

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Nov 19, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Does not affect a cysteine residue within a calcium-binding EGF-like domain of the FBN1 gene; cysteine substitutions in the calcium-binding EGF-like domains represent the majority of pathogenic missense changes associated with FBN1-related disorders (PMID: 12938084); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 25812041, 25637381, 26017485, 16222657, 24941995, 29543232, 12938084) -

Jan 09, 2015

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

GenomeConnect, ClinGen

Significance:not provided

Review Status:no classification provided

Collection Method:phenotyping only

Variant classified as Uncertain significance and reported on 01-28-2021 by GeneDx. GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -

Familial thoracic aortic aneurysm and aortic dissection

Pathogenic:1Uncertain:1Benign:2

Centre for Genomic and Experimental Medicine, University of Edinburgh

Significance:Likely pathogenic

Review Status:no assertion criteria provided

Collection Method:research

- -

Jul 22, 2022

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

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Feb 13, 2025

Ambry Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Jan 06, 2020

Color Diagnostics, LLC DBA Color Health

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Marfan syndrome

Uncertain:2

Dec 01, 2022

ClinGen FBN1 Variant Curation Expert Panel, ClinGen

Significance:Uncertain significance

Review Status:reviewed by expert panel

Collection Method:curation

The NM_000138 c.59A>G, is a missense variant in FBN1 predicted to cause a substitution of a Tyrosine by a Cysteine at amino acid 20 (p.Tyr20Cys). This variant was found in a proband with aortic root dilatation and a systemic score of 7 or above which is a highly specific phenotype for Marfan syndrome, however, a pathogenic splice variant in FBN1 was also identified in cis in this individual (BP2). The variant segregates with the disease in 4 affected family members, who also carry the pathogenic splice variant in FBN1. The variant in FBN1 has been reported 12 times in ClinVar: 3 times as likely benign, 8 times as uncertain significance and once as likely pathogenic (Variation ID: 161245). This variant has been identified in 37 individuals of European non-Finnish origin (MAF: 0.029%) (BS1; https://gnomad.broadinstitute.org/ version 2.1.1). The constraint z-score for missense variants affecting FBN1 is 5.06, however due to the presence of two benign arguments, PP2 cannot be used. In summary, this variant meets criteria to be classified as likely benign for Marfan syndrome based on the ACMG/AMP criteria applied, as specified by the ClinGen FBN1 VCEP: BS1, BP2 -

Jun 01, 2014

CSER _CC_NCGL, University of Washington

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:research

- -

not specified

Uncertain:1Benign:1

Mar 31, 2016

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant identified in a genome or exome case(s) and assessed due to predicted null impact of the variant or pathogenic assertions in the literature or databases. Disclaimer: This variant has not undergone full assessment. The following are preliminary notes: Multiple papers report as VUS; ExAC: 16/66648 Europeans; ClinVar: 1 LB, 2 VUS -

Nov 29, 2024

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

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: FBN1 c.59A>G (p.Tyr20Cys) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00015 in 251386 control chromosomes. The observed variant frequency is approximately 1.31 fold of the estimated maximal expected allele frequency for a pathogenic variant in FBN1 causing Marfan Syndrome phenotype (0.00011). This variant has been reported in multiple affected individuals without strong evidence for causality. Although, one paper, Yang_2014 indicates the variant does segregate with disease in the family, however, clinical information is not provided for additional family members. The following publications have been ascertained in the context of this evaluation (PMID: 16222657, 24941995, 26017485). ClinVar contains an entry for this variant (Variation ID: 161245). Based on the evidence outlined above, the variant was classified as likely benign. -

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

Benign:1

Jan 07, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.065

BayesDel_addAF

Benign

-0.049

BayesDel_noAF

Uncertain

0.0

CADD

Benign

(source)

DANN

Benign

0.96

DEOGEN2

Benign

0.38

.;T

Eigen

Benign

-0.34

Eigen_PC

Benign

-0.17

FATHMM_MKL

Benign

0.55

LIST_S2

Benign

0.76

T;T

M_CAP

Benign

0.084

MetaRNN

Benign

0.38

T;T

MetaSVM

Benign

-0.83

PhyloP100

3.9

PrimateAI

Uncertain

0.74

PROVEAN

Benign

-0.67

N;D

REVEL

Uncertain

0.37

Sift

Benign

0.17

T;D

Sift4G

Benign

0.19

T;T

Vest4

0.78

MVP

0.97

MPC

0.88

ClinPred

0.094

GERP RS

3.5

Mutation Taster

=78/22

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over