Genetic Variant FBN1:p.Thr1635Thr (chr15-48465605-G-C) – ACMG Classification: Benign (-21 pts)

Variant summary

Our verdict is Benign. The variant received -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_000138.5(FBN1):c.4905C>G(p.Thr1635Thr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00636 in 1,614,026 control chromosomes in the GnomAD database, including 41 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. T1635T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0042 ( 5 hom., cov: 32)

Exomes 𝑓: 0.0066 ( 36 hom. )

Consequence

FBN1
NM_000138.5 synonymous

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:27

Conservation

PhyloP100: -3.82

Publications

4 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: Benign. The variant received -21 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.85).

BP6

Variant 15-48465605-G-C is Benign according to our data. Variant chr15-48465605-G-C is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 36084.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BP7

Synonymous conserved (PhyloP=-3.82 with no splicing effect.

BS1

Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.00422 (642/152240) while in subpopulation NFE AF = 0.00679 (462/68016). AF 95% confidence interval is 0.00628. There are 5 homozygotes in GnomAd4. There are 294 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

BS2

High Homozygotes in GnomAd4 at 5 AD,AR,Unknown gene

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000138.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FBN1	NM_000138.5	MANE Select	c.4905C>G	p.Thr1635Thr	synonymous	Exon 40 of 66	NP_000129.3
	FBN1	NM_001406716.1		c.4905C>G	p.Thr1635Thr	synonymous	Exon 39 of 65	NP_001393645.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
FBN1	ENST00000316623.10	TSL:1 MANE Select	c.4905C>G	p.Thr1635Thr	synonymous	Exon 40 of 66	ENSP00000325527.5
FBN1	ENST00000559133.6	TSL:1	n.4905C>G		non_coding_transcript_exon	Exon 40 of 67	ENSP00000453958.2
FBN1	ENST00000537463.6	TSL:5	n.*668C>G		non_coding_transcript_exon	Exon 15 of 31	ENSP00000440294.2

Frequencies

GnomAD3 genomes

AF:

0.00422

AC:

642

AN:

152122

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00169

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00301

Gnomad ASJ

AF:

0.00605

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00274

Gnomad MID

AF:

0.00633

Gnomad NFE

AF:

0.00679

Gnomad OTH

AF:

0.00526

GnomAD2 exomes

AF:

0.00341

AC:

856

AN:

251284

AF XY:

0.00312

show subpopulations

Gnomad AFR exome

AF:

0.00123

Gnomad AMR exome

AF:

0.00173

Gnomad ASJ exome

AF:

0.00397

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00286

Gnomad NFE exome

AF:

0.00551

Gnomad OTH exome

AF:

0.00669

GnomAD4 exome

AF:

0.00658

AC:

9624

AN:

1461786

Hom.:

Cov.:

AF XY:

0.00630

AC XY:

4584

AN XY:

727192

show subpopulations

African (AFR)

AF:

0.000986

AC:

AN:

33478

American (AMR)

AF:

0.00183

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00417

AC:

109

AN:

26132

East Asian (EAS)

AF:

0.00

AC:

AN:

39696

South Asian (SAS)

AF:

0.000278

AC:

AN:

86252

European-Finnish (FIN)

AF:

0.00285

AC:

152

AN:

53418

Middle Eastern (MID)

AF:

0.00156

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.00788

AC:

8760

AN:

1111926

Other (OTH)

AF:

0.00753

AC:

455

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.454

Heterozygous variant carriers

494

988

1482

1976

2470

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

350

700

1050

1400

1750

<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:

0.00422

AC:

642

AN:

152240

Hom.:

Cov.:

AF XY:

0.00395

AC XY:

294

AN XY:

74420

show subpopulations

African (AFR)

AF:

0.00168

AC:

AN:

41548

American (AMR)

AF:

0.00301

AC:

AN:

15300

Ashkenazi Jewish (ASJ)

AF:

0.00605

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5176

South Asian (SAS)

AF:

0.000208

AC:

AN:

4818

European-Finnish (FIN)

AF:

0.00274

AC:

AN:

10594

Middle Eastern (MID)

AF:

0.00680

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00679

AC:

462

AN:

68016

Other (OTH)

AF:

0.00521

AC:

AN:

2112

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.501

Heterozygous variant carriers

102

136

170

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Genome Hom

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:

0.00395

Hom.:

Bravo

AF:

0.00401

EpiCase

AF:

0.00627

EpiControl

AF:

0.00670

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:27

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:6

Jun 22, 2013

GeneDx

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease.

Nov 07, 2007

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Jul 12, 2016

Eurofins Ntd Llc (ga)

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

PreventionGenetics, part of Exact Sciences

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Genome Diagnostics Laboratory, Amsterdam University Medical Center

Significance:Benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

Apr 09, 2025

Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Marfan syndrome

Benign:5

Aug 24, 2015

Genomic Diagnostic Laboratory, Division of Genomic Diagnostics, Children's Hospital of Philadelphia

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Sep 23, 2022

Cohesion Phenomics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Jun 01, 2018

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

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease.

Feb 03, 2012

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

Significance:Benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

not provided

Benign:5

Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

Nov 04, 2024

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Breakthrough Genomics, Breakthrough Genomics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:not provided

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

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

Aug 01, 2025

CeGaT Center for Human Genetics Tuebingen

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

FBN1: BP4, BP7, BS2

Familial thoracic aortic aneurysm and aortic dissection

Benign:4

Mar 08, 2018

Color Diagnostics, LLC DBA Color Health

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Aug 26, 2014

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 13, 2018

Illumina Laboratory Services, Illumina

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease.

Feb 24, 2016

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

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Stiff skin syndrome

Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Weill-Marchesani syndrome

Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Geleophysic dysplasia

Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Acromicric dysplasia

Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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

Benign:1

Feb 03, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Ectopia lentis 1, isolated, autosomal dominant

Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Connective tissue disorder

Benign:1

Dec 20, 2021

Genome Diagnostics Laboratory, The Hospital for Sick Children

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.85

CADD

Benign

0.056

(source)

DANN

Benign

0.57

PhyloP100

-3.8

Mutation Taster

=86/14

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.040

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

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over