rs760170973

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1PM2PP2

The NM_000138.5(FBN1):​c.5674A>T​(p.Ile1892Leu) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.000000693 in 1,442,210 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

FBN1
NM_000138.5 missense, splice_region

Scores

1
10
6

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.81
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 Uncertain_significance. Variant got 5 ACMG points.

PM1
In a domain EGF-like 32; calcium-binding (size 38) in uniprot entity FBN1_HUMAN there are 17 pathogenic changes around while only 0 benign (100%) 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.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
FBN1NM_000138.5 linkc.5674A>T p.Ile1892Leu missense_variant, splice_region_variant Exon 47 of 66 ENST00000316623.10 NP_000129.3 P35555
FBN1NM_001406716.1 linkc.5674A>T p.Ile1892Leu missense_variant, splice_region_variant Exon 46 of 65 NP_001393645.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
FBN1ENST00000316623.10 linkc.5674A>T p.Ile1892Leu missense_variant, splice_region_variant Exon 47 of 66 1 NM_000138.5 ENSP00000325527.5 P35555

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.93e-7
AC:
1
AN:
1442210
Hom.:
0
Cov.:
26
AF XY:
0.00000139
AC XY:
1
AN XY:
718898
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:
9.14e-7
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Marfan syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection Uncertain:1
Feb 27, 2018
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with FBN1-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces isoleucine with leucine at codon 1892 of the FBN1 protein (p.Ile1892Leu). The isoleucine residue is moderately conserved and there is a small physicochemical difference between isoleucine and leucine. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.28
BayesDel_addAF
Uncertain
0.075
D
BayesDel_noAF
Benign
-0.13
CADD
Pathogenic
26
DANN
Uncertain
0.99
Eigen
Uncertain
0.60
Eigen_PC
Uncertain
0.63
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Benign
0.73
T
M_CAP
Benign
0.051
D
MetaRNN
Uncertain
0.55
D
MetaSVM
Uncertain
0.45
D
PrimateAI
Uncertain
0.55
T
PROVEAN
Benign
-1.8
N
REVEL
Uncertain
0.54
Sift
Uncertain
0.011
D
Sift4G
Uncertain
0.033
D
Vest4
0.39
MutPred
0.76
Gain of disorder (P = 0.1388);
MVP
0.53
MPC
0.62
ClinPred
0.64
D
GERP RS
6.1

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: rs760170973; hg19: chr15-48739017; API