NM_000138.5:c.1286G>C

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 1P and 5B. PP2BP4BS2

The NM_000138.5(FBN1):​c.1286G>C​(p.Arg429Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,048 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

FBN1
NM_000138.5 missense

Scores

4
13

Clinical Significance

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

Conservation

PhyloP100: 2.22
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 Likely_benign. Variant got -4 ACMG points.

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.
BP4
Computational evidence support a benign effect (MetaRNN=0.31417045).
BS2
High AC in GnomAdExome4 at 5 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
FBN1NM_000138.5 linkc.1286G>C p.Arg429Pro missense_variant Exon 11 of 66 ENST00000316623.10 NP_000129.3 P35555
FBN1NM_001406716.1 linkc.1286G>C p.Arg429Pro missense_variant Exon 10 of 65 NP_001393645.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
FBN1ENST00000316623.10 linkc.1286G>C p.Arg429Pro missense_variant Exon 11 of 66 1 NM_000138.5 ENSP00000325527.5 P35555
FBN1ENST00000559133.6 linkn.1286G>C non_coding_transcript_exon_variant Exon 11 of 67 1 ENSP00000453958.2 H0YND0
FBN1ENST00000674301.2 linkn.1286G>C non_coding_transcript_exon_variant Exon 11 of 68 ENSP00000501333.2 A0A6I8PL22
FBN1ENST00000537463.6 linkn.636+21487G>C intron_variant Intron 7 of 30 5 ENSP00000440294.2 F6U495

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
151444
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:
0.000482
GnomAD4 exome
AF:
0.00000342
AC:
5
AN:
1461604
Hom.:
0
Cov.:
33
AF XY:
0.00000550
AC XY:
4
AN XY:
727114
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:
0.00000450
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000132
AC:
2
AN:
151444
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
73888
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:
0.000482
Bravo
AF:
0.00000756

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Dec 02, 2024
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.1286G>C (p.Arg429Pro) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant was absent in 251256 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1286G>C has been reported in the literature in at least an individual affected with Marfan Syndrome (example: Aubart_2018). This report however, does not provide unequivocal conclusions about association of the variant with Marfan Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 30087447, 34220303). ClinVar contains an entry for this variant (Variation ID: 1768977). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1
Oct 21, 2019
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The p.R429P variant (also known as c.1286G>C), located in coding exon 10 of the FBN1 gene, results from a G to C substitution at nucleotide position 1286. The arginine at codon 429 is replaced by proline, an amino acid with dissimilar properties, and is located in the proline-rich region. This variant was reported to occur in trans with an FBN1 pathogenic variant in an individual from a Marfan syndrome cohort (Aubart M et al. Eur. J. Hum. Genet., 2018 12;26:1759-1772). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1
Dec 05, 2023
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 does not alter protein structure/function; Does not affect a cysteine residue within a calcium-binding EGF-like domain or a TGF-binding protein domain of the FBN1 gene; cysteine substitutions in the calcium-binding EGF-like domains represent the majority of pathogenic missense changes associated with FBN1-related disorders (PMID: 12938084); This variant is associated with the following publications: (PMID: 34220303, 30087447, 12938084) -

Marfan syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection Uncertain:1
Feb 23, 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 proline, which is neutral and non-polar, at codon 429 of the FBN1 protein (p.Arg429Pro). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with Marfan syndrome (PMID: 30087447). ClinVar contains an entry for this variant (Variation ID: 1768977). 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 with a negative 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
Benign
0.091
BayesDel_addAF
Uncertain
0.059
T
BayesDel_noAF
Benign
-0.15
CADD
Benign
21
DANN
Uncertain
0.99
Eigen
Uncertain
0.21
Eigen_PC
Uncertain
0.32
FATHMM_MKL
Benign
0.67
D
LIST_S2
Benign
0.83
T
M_CAP
Benign
0.058
D
MetaRNN
Benign
0.31
T
MetaSVM
Benign
-0.61
T
PrimateAI
Benign
0.46
T
PROVEAN
Benign
-0.82
N
REVEL
Benign
0.29
Sift
Benign
0.29
T
Sift4G
Benign
0.24
T
Vest4
0.43
MutPred
0.38
Gain of glycosylation at R429 (P = 0.006);
MVP
0.69
MPC
0.76
ClinPred
0.55
D
GERP RS
5.5

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: rs368089138; hg19: chr15-48808421; API