rs864622676

chr15-48448884-T-C

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Moderate

The NM_000138.5(FBN1):c.5555A>G(p.Glu1852Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 11/18 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E1852A) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: FBN1 NM_000138.5 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 8.01

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]

ACMG classification

Verdict is Pathogenic. Variant got 13 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 uncertain in NM_000138.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr15-48448884-T-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2922440.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP2: Missense variant where missense usually causes diseases, FBN1
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991
• PP5: Variant 15-48448884-T-C is Pathogenic according to our data. Variant chr15-48448884-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 220855.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr15-48448884-T-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FBN1	NM_000138.5	c.5555A>G	p.Glu1852Gly	missense_variant	46/66	ENST00000316623.10
FBN1	NM_001406716.1	c.5555A>G	p.Glu1852Gly	missense_variant	45/65

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FBN1	ENST00000316623.10	c.5555A>G	p.Glu1852Gly	missense_variant	46/66	1	NM_000138.5	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Marfan syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Aug 12, 2021

This sequence change replaces glutamic acid with glycine at codon 1852 of the FBN1 protein (p.Glu1852Gly). The glutamic acid residue is highly conserved and there is a moderate physicochemical difference between glutamic acid and glycine. This variant is not present in population databases (ExAC no frequency). This variant has been observed in individual(s) with clinical features of FBN1-related conditions (Invitae). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 220855). 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. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.47
Cadd	Pathogenic	31
Dann	Pathogenic	1.0
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.93
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D
M_CAP	Pathogenic	0.84	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.71	T
PROVEAN	Pathogenic	-6.5	D
REVEL	Pathogenic	0.94
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.0090	D
Vest4		0.84
MutPred		0.93		Loss of disorder (P = 0.1379);
MVP		0.92
MPC		1.5
ClinPred		1.0	D
GERP RS		6.2

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

Other links and lift over

dbSNP: rs864622676; hg19: chr15-48741081;