chr15-48489907-G-A

Position:

• chr15-48489907-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 5P and 4B. PM1 PP2 PP3_Moderate BS2

The NM_000138.5(FBN1):​c.3026C>T​(p.Pro1009Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,461,888 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P1009R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000055 (1 hom.)
• Consequence: FBN1 NM_000138.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 10.0

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 Uncertain_significance. Variant got 1 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 5 uncertain in NM_000138.5
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), FBN1. . Gene score misZ 5.0644 (greater than the threshold 3.09). Trascript score misZ 8.1787 (greater than threshold 3.09). GenCC has associacion of gene with 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.925
• BS2: High AC in GnomAdExome4 at 8 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FBN1	NM_000138.5	c.3026C>T	p.Pro1009Leu	missense_variant	25/66	ENST00000316623.10
FBN1	NM_001406716.1	c.3026C>T	p.Pro1009Leu	missense_variant	24/65

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FBN1	ENST00000316623.10	c.3026C>T	p.Pro1009Leu	missense_variant	25/66	1	NM_000138.5	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461888 Hom.: 1 Cov.: 31 AF XY: 0.00000825 AC XY: 6 AN XY: 727246

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: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000450

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 31

Bravo AF: 0.00000378

EpiCase AF: 0.000164

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Marfan syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

May 23, 2023

This missense variant replaces proline with leucine at codon 1009 of the FBN1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in one individual affected with left ventricular non-compaction (PMID: 30471092). This variant has not been identified 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 03, 2021

This missense variant replaces proline with leucine at codon 1009 of the FBN1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in one individual affected with left ventricular non‐compaction (PMID: 30471092). This variant has not been identified 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

Uncertain significance, criteria provided, single submitter

not provided

Breakthrough Genomics, Breakthrough Genomics

-

- -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 26, 2023

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 1009 of the FBN1 protein (p.Pro1009Leu). 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. 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. ClinVar contains an entry for this variant (Variation ID: 925193). This variant has not been reported in the literature in individuals affected with FBN1-related conditions. This variant is not present in population databases (gnomAD no frequency). -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Jul 26, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.36
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.36
CADD	Pathogenic	31
DANN	Pathogenic	1.0
Eigen	Pathogenic	0.95
Eigen_PC	Pathogenic	0.92
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Pathogenic	0.67	D
MetaRNN	Pathogenic	0.93	D
MetaSVM	Pathogenic	0.98	D
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.78	T
PROVEAN	Pathogenic	-8.5	D
REVEL	Pathogenic	0.85
Sift	Benign	0.053	T
Sift4G	Pathogenic	0.0010	D
Vest4		0.91
MutPred		0.46		Loss of disorder (P = 0.0165);
MVP		0.89
MPC		1.4
ClinPred		0.99	D
GERP RS		5.6

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: rs148076256; hg19: chr15-48782104;