15-48412577-T-C

Position:

chr15-48412577-T-C

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 1P and 2B. PP2BP4_Moderate

The NM_000138.5(FBN1):c.8218A>G(p.Asn2740Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,613,960 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/18 in silico tools predict a benign outcome for this variant. 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. N2740S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

FBN1
NM_000138.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: -0.456

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 Likely_benign. Variant got -1 ACMG points.

PP2

Missense variant in gene, where missense usually causes diseases (based on misZ statistic), FBN1. . Gene score misZ 5.0644 (greater than the threshold 3.09). Trascript score misZ 8.1787 (greater than threshold 3.09). GenCC has associacion of gene with 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.

BP4

Computational evidence support a benign effect (MetaRNN=0.075513095).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FBN1	NM_000138.5 linkuse as main transcript	c.8218A>G	p.Asn2740Asp	missense_variant	65/66	ENST00000316623.10
FBN1	NM_001406716.1 linkuse as main transcript	c.8218A>G	p.Asn2740Asp	missense_variant	64/65

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FBN1	ENST00000316623.10 linkuse as main transcript	c.8218A>G	p.Asn2740Asp	missense_variant	65/66	1	NM_000138.5	P1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152204

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000796

AC:

AN:

251258

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135802

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 SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1461756

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

727162

show subpopulations

Gnomad4 AFR exome

AF:

0.00

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:

0.00000360

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152204

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74362

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:

0.0000294

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Marfan syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Nov 28, 2023

This missense variant replaces asparagine with aspartic acid at codon 2740 of the FBN1 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with thoracic aortic aneurysm and dissection (PMID: 24793577). This variant has been identified in 2/251258 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. -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Mar 05, 2013

The Asn2740Asp variant in FBN1 has not been reported in the literature, but it h as previously been identified by our laboratory in one individual with clinical features of familial thoracic aortic aneurysm and dissection (TAAD). The Asn2740 residue is not well conserved in mammalian species and is replaced by the varia nt residue, Asp, in the Rat and Mouse. In addition, computational analyses (bioc hemical amino acid properties, AlignGVGD, PolyPhen2, and SIFT) suggest that the Asn2740Asp variant may not impact the protein, though this information is not pr edictive enough to rule out pathogenicity. This variant has also not been identi fied in large European American and African American populations by the NHLBI Ex ome Sequencing Project (http://evs.gs.washington.edu/EVS), though it may be pres ent in other populations. In summary, additional information is needed to fully assess the clinical significance of the Asn2740Asp variant. -

Familial thoracic aortic aneurysm and aortic dissection

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 02, 2022

The p.N2740D variant (also known as c.8218A>G), located in coding exon 64 of the FBN1 gene, results from an A to G substitution at nucleotide position 8218. The asparagine at codon 2740 is replaced by aspartic acid, an amino acid with highly similar properties. In a study of patients undergoing clinical aortopathy genetic testing, this alteration was reported in a single individual with thoracic aortic aneurysm and dissection; however, clinical details were limited (Lerner-Ellis JP et al. Mol. Genet. Metab., 2014 Jun;112:171-6). From this same study, another alteration affecting this amino acid (p.N2740S, c.8219A>G) was reported in a single individual with suspected Marfan syndrome. This amino acid position is not well conserved in available vertebrate species, and aspartic acid is the reference amino acid in other vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 19, 2023

This sequence change replaces asparagine, which is neutral and polar, with aspartic acid, which is acidic and polar, at codon 2740 of the FBN1 protein (p.Asn2740Asp). 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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt FBN1 protein function. ClinVar contains an entry for this variant (Variation ID: 42440). This missense change has been observed in individuals with aortic aneurysm and/or aortic dilation (PMID: 24793577; Invitae). This variant is present in population databases (rs397515860, gnomAD 0.002%). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.059

BayesDel_addAF

Benign

-0.20

BayesDel_noAF

Benign

-0.51

CADD

Benign

0.061

DANN

Benign

0.39

Eigen

Benign

-1.7

Eigen_PC

Benign

-1.8

FATHMM_MKL

Benign

0.036

LIST_S2

Benign

0.56

M_CAP

Uncertain

0.11

MetaRNN

Benign

0.076

MetaSVM

Benign

-0.93

MutationTaster

Benign

1.0

PrimateAI

Benign

0.28

PROVEAN

Benign

0.48

REVEL

Benign

0.19

Sift

Benign

0.70

Sift4G

Benign

0.70

Vest4

0.23

MutPred

0.19

Loss of MoRF binding (P = 0.1127);

MVP

0.65

MPC

0.57

ClinPred

0.0089

GERP RS

-11

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