NM_000138.5:c.3145G>A

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 9P and 4B. PM1PM5PP2PP3_StrongBS2

The NM_000138.5(FBN1):​c.3145G>A​(p.Gly1049Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000026 in 1,614,026 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 11/18 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G1049C) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000025 ( 0 hom. )

Consequence

FBN1
NM_000138.5 missense

Scores

13
1
3

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:7

Conservation

PhyloP100: 7.91
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PM1
In a disulfide_bond (size 14) in uniprot entity FBN1_HUMAN there are 9 pathogenic changes around while only 0 benign (100%) in NM_000138.5
PM5
Other missense variant is known to change same aminoacid residue: Variant chr15-48488431-C-A is described in Lovd as [Likely_pathogenic].
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, 0.943
BS2
High AC in GnomAd4 at 5 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
FBN1NM_000138.5 linkc.3145G>A p.Gly1049Ser missense_variant Exon 26 of 66 ENST00000316623.10 NP_000129.3 P35555
FBN1NM_001406716.1 linkc.3145G>A p.Gly1049Ser missense_variant Exon 25 of 65 NP_001393645.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
FBN1ENST00000316623.10 linkc.3145G>A p.Gly1049Ser missense_variant Exon 26 of 66 1 NM_000138.5 ENSP00000325527.5 P35555

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152146
Hom.:
0
Cov.:
32
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:
0.0000735
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000159
AC:
4
AN:
251486
Hom.:
0
AF XY:
0.00
AC XY:
0
AN XY:
135914
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000578
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:
0.0000253
AC:
37
AN:
1461880
Hom.:
0
Cov.:
33
AF XY:
0.0000234
AC XY:
17
AN XY:
727244
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000447
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:
0.0000288
Gnomad4 OTH exome
AF:
0.0000497
GnomAD4 genome
AF:
0.0000329
AC:
5
AN:
152146
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74326
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:
0.0000735
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000847
Hom.:
0
Bravo
AF:
0.0000302
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.000109
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:7
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:3
-
Genome Diagnostics Laboratory, University Medical Center Utrecht
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Mar 09, 2023
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The p.Gly1049Ser variant in FBN1 has not been previously reported in individuals with Marfan syndrome or familial thoracic aortic aneurysm and was absent from large population studies. This variant has also been reported in ClinVar (Variation ID 457190). Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. One variant involving this codon (p.Gly1049Asp) has been identified in individuals with Marfan syndrome or thoracic aortic aneurysm and dissection. In summary, the clinical significance of this variant is uncertain. ACMG/AMP Criteria applied: PP3. -

-
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

- -

Marfan syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection Pathogenic:1
Aug 03, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 1049 of the FBN1 protein (p.Gly1049Ser). This variant is present in population databases (rs778181932, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with FBN1-related conditions. ClinVar contains an entry for this variant (Variation ID: 457190). 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 expected to disrupt FBN1 protein function with a positive predictive value of 95%. This variant disrupts the p.Gly1049 amino acid residue in FBN1. Other variant(s) that disrupt this residue have been determined to be pathogenic (Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Marfan syndrome Uncertain:1
Sep 11, 2024
All of Us Research Program, National Institutes of Health
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This missense variant replaces glycine with serine at codon 1049 of the FBN1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with cardiovascular disorders in the literature. This variant has been identified in 5/282892 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
Jul 10, 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.3145G>A (p.Gly1049Ser) results in a non-conservative amino acid change located in the EGF-like domain (IPR000742) 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 1.6e-05 in 251486 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.3145G>A in individuals affected with Marfan Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Three ClinVar submitters have assessed the variant since 2014: two classified the variant as uncertain significance and one as likely pathogenic. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1
Oct 12, 2023
Color Diagnostics, LLC DBA Color Health
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This missense variant replaces glycine with serine at codon 1049 of the FBN1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with FBN1-related disorders in the literature. This variant has been identified in 5/282892 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. -

Progeroid and marfanoid aspect-lipodystrophy syndrome Uncertain:1
May 10, 2019
Centre for Mendelian Genomics, University Medical Centre Ljubljana
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant was classified as: Uncertain significance. The available evidence on this variant's pathogenicity is insufficient or conflicting. The following ACMG criteria were applied in classifying this variant: PM1,,PM5,PP3. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.84
BayesDel_addAF
Pathogenic
0.27
D
BayesDel_noAF
Pathogenic
0.33
CADD
Pathogenic
29
DANN
Uncertain
1.0
Eigen
Pathogenic
1.0
Eigen_PC
Pathogenic
1.0
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.99
D
M_CAP
Pathogenic
0.87
D
MetaRNN
Pathogenic
0.94
D
MetaSVM
Pathogenic
1.0
D
PrimateAI
Pathogenic
0.81
D
PROVEAN
Pathogenic
-5.3
D
REVEL
Pathogenic
0.79
Sift
Benign
0.049
D
Sift4G
Benign
0.069
T
Vest4
0.84
MVP
0.88
MPC
1.4
ClinPred
0.98
D
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.

Other links and lift over

dbSNP: rs778181932; hg19: chr15-48780628; API