rs377338217

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 5P and 2B. PM1PM2PP2BP4_Moderate

The NM_000138.5(FBN1):c.4306G>T(p.Val1436Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,856 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V1436M) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

FBN1
NM_000138.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:1

Conservation

PhyloP100: 2.42

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 10 uncertain in NM_000138.5

PM2

Very rare variant in population databases, with high coverage;

PP2

Missense variant where missense usually causes diseases, FBN1

BP4

Computational evidence support a benign effect (MetaRNN=0.21409449).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FBN1	NM_000138.5 linkuse as main transcript	c.4306G>T	p.Val1436Leu	missense_variant	35/66	ENST00000316623.10
FBN1	NM_001406716.1 linkuse as main transcript	c.4306G>T	p.Val1436Leu	missense_variant	34/65

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FBN1	ENST00000316623.10 linkuse as main transcript	c.4306G>T	p.Val1436Leu	missense_variant	35/66	1	NM_000138.5	P1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000796

AC:

AN:

251344

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135846

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

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:

0.00000137

AC:

AN:

1461856

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727228

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:

0.00000180

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Bravo

AF:

0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Marfan syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Dec 07, 2023

This missense variant replaces valine with leucine at codon 1436 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). Splice site prediction tools suggest that this variant may not impact RNA splicing. 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 2/251344 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. -

Familial thoracic aortic aneurysm and aortic dissection

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Mar 18, 2020

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 19, 2017

The V1436L variant in the FBN1 gene has not been reported previously as a pathogenic variant, nor as a benign variant, to our knowledge. This variant is not observed in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). The V1436L variant is a conservative amino acid substitution, which is not likely to impact secondary protein structure as these residues share similar properties. This substitution occurs at a position where amino acids with similar properties to Valine are tolerated across species. In silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. We interpret V1436L as a variant of uncertain significance. -

Marfan syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Jan 29, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.077

BayesDel_addAF

Benign

-0.040

BayesDel_noAF

Benign

-0.28

Cadd

Benign

Dann

Uncertain

0.99

Eigen

Benign

-0.20

Eigen_PC

Benign

0.051

FATHMM_MKL

Uncertain

0.86

LIST_S2

Benign

0.69

M_CAP

Benign

0.019

MetaRNN

Benign

0.21

MetaSVM

Uncertain

-0.16

MutationTaster

Benign

0.82

PrimateAI

Uncertain

0.57

PROVEAN

Benign

-0.84

REVEL

Uncertain

0.35

Sift

Benign

0.67

Sift4G

Benign

0.67

Vest4

0.26

MutPred

0.45

Gain of disorder (P = 0.1528);

MVP

0.41

MPC

0.50

ClinPred

0.23

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over