rs748327743

Variant names:

Your query was ambiguous. Multiple possible variants found:

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PM2PP2

The NM_000138.5(FBN1):c.8327G>T(p.Arg2776Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,806 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R2776Q) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

FBN1
NM_000138.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.11

Publications

3 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.

PM1

In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 13 uncertain in NM_000138.5

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 Marfan syndrome, Weill-Marchesani syndrome 2, dominant, progeroid and marfanoid aspect-lipodystrophy syndrome, geleophysic dysplasia, Shprintzen-Goldberg syndrome, stiff skin syndrome, familial thoracic aortic aneurysm and aortic dissection, isolated ectopia lentis, ectopia lentis 1, isolated, autosomal dominant, Acromicric dysplasia, neonatal Marfan syndrome, Weill-Marchesani syndrome.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FBN1	NM_000138.5 link	c.8327G>T	p.Arg2776Leu	missense_variant	Exon 66 of 66	ENST00000316623.10	NP_000129.3	P35555
FBN1	NM_001406716.1 link	c.8327G>T	p.Arg2776Leu	missense_variant	Exon 65 of 65		NP_001393645.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FBN1	ENST00000316623.10 link	c.8327G>T	p.Arg2776Leu	missense_variant	Exon 66 of 66	1	NM_000138.5	ENSP00000325527.5		P35555

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

0.00000342

AC:

AN:

1461806

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727204

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.00

AC:

AN:

39688

South Asian (SAS)

AF:

0.00

AC:

AN:

86250

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53410

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000450

AC:

AN:

1111960

Other (OTH)

AF:

0.00

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.465

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome 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

GnomAD4 genome

Cov.:

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

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

Uncertain:1

Sep 11, 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 leucine, which is neutral and non-polar, at codon 2776 of the FBN1 protein (p.Arg2776Leu). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with FBN1-related conditions. 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) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on FBN1 protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.39

BayesDel_addAF

Pathogenic

0.30

BayesDel_noAF

Pathogenic

0.19

CADD

Pathogenic

(source)

DANN

Uncertain

0.99

Eigen

Uncertain

0.24

Eigen_PC

Uncertain

0.37

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.95

M_CAP

Benign

0.066

MetaRNN

Uncertain

0.61

MetaSVM

Uncertain

-0.12

PhyloP100

2.1

PrimateAI

Benign

0.33

PROVEAN

Uncertain

-4.1

REVEL

Uncertain

0.59

Sift

Uncertain

0.026

Sift4G

Benign

0.10

Vest4

0.55

MutPred

0.58

Gain of sheet (P = 0.0101);

MVP

0.88

MPC

0.90

ClinPred

0.98

GERP RS

5.5

Mutation Taster

=55/45

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.10

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

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over