rs1232797551

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1PM2PP2PP3_Moderate

The NM_000138.5(FBN1):​c.5347A>T​(p.Ile1783Phe) variant causes a missense change. The variant allele was found at a frequency of 0.00000124 in 1,613,824 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

FBN1
NM_000138.5 missense

Scores

11
4
2

Clinical Significance

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

Conservation

PhyloP100: 6.25
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]

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

PM1
In a domain EGF-like 29; calcium-binding (size 41) in uniprot entity FBN1_HUMAN there are 11 pathogenic changes around while only 1 benign (92%) 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 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, 0.886

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
FBN1NM_000138.5 linkc.5347A>T p.Ile1783Phe missense_variant Exon 44 of 66 ENST00000316623.10 NP_000129.3 P35555
FBN1NM_001406716.1 linkc.5347A>T p.Ile1783Phe missense_variant Exon 43 of 65 NP_001393645.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
FBN1ENST00000316623.10 linkc.5347A>T p.Ile1783Phe missense_variant Exon 44 of 66 1 NM_000138.5 ENSP00000325527.5 P35555

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152180
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461644
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
727146
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:
8.99e-7
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152180
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
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:
0.0000147
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
Feb 24, 2023
All of Us Research Program, National Institutes of Health
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant of Uncertain Significance due to insufficient evidence: This missense variant is located in the calcium-binding EGF-like motif 29 of the FBN1 protein. Computational prediction tools and conservation analyses suggest that this variant may have deleterious impact on the protein function. Computational splicing tools suggest that this variant may not impact RNA splicing. To our knowledge, functional assays have not been performed for this variant nor has this variant been reported in individuals affected with cardiovascular disorders in the literature. This variant is rare in the general population and has been identified in 0/277264 chromosomes by the Genome Aggregation Database (gnomAD). Available evidence is insufficient to determine the role of this variant in disease conclusively. -

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1
Jan 18, 2023
Color Diagnostics, LLC DBA Color Health
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This missense variant replaces isoleucine with phenylalanine at codon 1783 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 not been identified 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 provided Uncertain:1
Jul 15, 2022
GeneDx
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Although located in a calcium-binding EGF-like domain of the FBN1 gene, it does not affect a cysteine residue within this domain; cysteine substitutions in the calcium-binding EGF-like domains represent the majority of pathogenic missense changes associated with FBN1-related disorders (Collod-Beroud et al., 2003); Identified in an individual with a Progeroid phenotype in published literature (Grelet M et al., 2019), additional details were not provided; This variant is associated with the following publications: (PMID: 12938084, 31829210) -

Marfan syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection Uncertain:1
May 13, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 1783 of the FBN1 protein (p.Ile1783Phe). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of FBN1-related conditions (PMID: 31829210). ClinVar contains an entry for this variant (Variation ID: 457229). 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%. 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
Pathogenic
0.61
BayesDel_addAF
Pathogenic
0.32
D
BayesDel_noAF
Pathogenic
0.23
CADD
Pathogenic
26
DANN
Uncertain
0.99
Eigen
Pathogenic
0.69
Eigen_PC
Pathogenic
0.70
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.91
D
M_CAP
Pathogenic
0.58
D
MetaRNN
Pathogenic
0.89
D
MetaSVM
Pathogenic
0.95
D
PrimateAI
Pathogenic
0.81
D
PROVEAN
Uncertain
-3.3
D
REVEL
Pathogenic
0.79
Sift
Uncertain
0.0050
D
Sift4G
Benign
0.070
T
Vest4
0.69
MutPred
0.56
Gain of catalytic residue at I1783 (P = 0.0502);
MVP
0.84
MPC
1.7
ClinPred
0.98
D
GERP RS
5.8

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: rs1232797551; hg19: chr15-48748909; API