15-48463965-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 3P and 2B. PM1PP2BP4_Moderate

The NM_000138.5(FBN1):​c.4999G>A​(p.Val1667Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000285 in 1,613,448 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/19 in silico tools predict a benign 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. V1667L) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

FBN1
NM_000138.5 missense

Scores

2
15

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:1

Conservation

PhyloP100: 0.496

Publications

6 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)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PM1
In a hotspot region, there are 18 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_000138.5
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.
BP4
Computational evidence support a benign effect (MetaRNN=0.10962096).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
FBN1NM_000138.5 linkc.4999G>A p.Val1667Ile missense_variant Exon 41 of 66 ENST00000316623.10 NP_000129.3 P35555
FBN1NM_001406716.1 linkc.4999G>A p.Val1667Ile missense_variant Exon 40 of 65 NP_001393645.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
FBN1ENST00000316623.10 linkc.4999G>A p.Val1667Ile missense_variant Exon 41 of 66 1 NM_000138.5 ENSP00000325527.5 P35555

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152178
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000358
AC:
9
AN:
251208
AF XY:
0.0000368
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.0000579
Gnomad ASJ exome
AF:
0.0000993
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000264
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000287
AC:
42
AN:
1461270
Hom.:
0
Cov.:
31
AF XY:
0.0000316
AC XY:
23
AN XY:
726966
show subpopulations
African (AFR)
AF:
0.0000897
AC:
3
AN:
33456
American (AMR)
AF:
0.0000447
AC:
2
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26126
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39672
South Asian (SAS)
AF:
0.0000580
AC:
5
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53410
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000270
AC:
30
AN:
1111504
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60366
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.477
Heterozygous variant carriers
0
3
6
8
11
14
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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
AF:
0.0000263
AC:
4
AN:
152178
Hom.:
0
Cov.:
33
AF XY:
0.0000538
AC XY:
4
AN XY:
74346
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41452
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68020
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.550
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000602
Hom.:
0
Bravo
AF:
0.0000302
ExAC
AF:
0.0000412
AC:
5
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:5Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Marfan syndrome Uncertain:1
Nov 02, 2023
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 valine with isoleucine at codon 1667 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 Marfan syndrome or a related connective tissue disorder (PMID: 10464652). This variant has been identified in 10/282608 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
Jan 23, 2019
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The FBN1 c.4999G>A; p.Val1667Ile variant (rs140626) has been described in at least one individual affected with Marfan syndrome or a related connective tissue disorder (Liu 1997). It contains an entry in ClinVar (Variation ID: 406339) and is observed in the general population at a low overall frequency of 0.0035% (10/282608 alleles) in the Genome Aggregation Database. The valine at codon 1667 is moderately conserved, and computational algorithms (PolyPhen-2, SIFT) predict that this variant is tolerated. However, due to limited information regarding this variant, its clinical significance cannot be determined with certainty. REFERENCES Liu W et al. Denaturing HPLC-identified novel FBN1 mutations, polymorphisms, and sequence variants in Marfan syndrome and related connective tissue disorders. Genet Test. 1997;1(4):237-42. -

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1
Sep 07, 2023
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces valine with isoleucine at codon 1667 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 not been reported in individuals affected with FBN1-related disorders in the literature. This variant has been identified in 10/282608 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 provided Uncertain:1
May 16, 2023
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant does not alter 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); This variant is associated with the following publications: (PMID: 11875032, 10464652, 11461921) -

Marfan syndrome;C0265287:Acromicric dysplasia;C1858556:MASS syndrome;C1861456:Stiff skin syndrome;C1869115:Weill-Marchesani syndrome 2, dominant;C3280054:Geleophysic dysplasia 2;C3541518:Ectopia lentis 1, isolated, autosomal dominant;C4310796:Progeroid and marfanoid aspect-lipodystrophy syndrome Uncertain:1
Mar 24, 2022
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Marfan syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection Benign:1
Jan 28, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.073
BayesDel_addAF
Benign
-0.21
T
BayesDel_noAF
Benign
-0.35
CADD
Benign
18
DANN
Uncertain
0.98
Eigen
Benign
-0.66
Eigen_PC
Benign
-0.55
FATHMM_MKL
Benign
0.27
N
LIST_S2
Benign
0.50
T
M_CAP
Benign
0.047
D
MetaRNN
Benign
0.11
T
MetaSVM
Benign
-0.41
T
PhyloP100
0.50
PrimateAI
Uncertain
0.68
T
PROVEAN
Benign
0.13
N
REVEL
Benign
0.20
Sift
Benign
0.45
T
Sift4G
Benign
0.22
T
Vest4
0.11
MutPred
0.54
Loss of catalytic residue at V1667 (P = 0.1818);
MVP
0.23
MPC
0.45
ClinPred
0.081
T
GERP RS
3.7
Mutation Taster
=86/14
polymorphism

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

Other links and lift over

dbSNP: rs140626; hg19: chr15-48756162; COSMIC: COSV57320973; API