NM_000138.5:c.4466A>G

Variant names:

• chr15-48468528-T-C
• rs1057518501
• NM_000138.5:c.4466A>G

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2 PP2 PM5

This summary comes from the ClinGen Evidence Repository: The NM_000138 c.4466A>G variant is a missense variant in FBN1 predicted to cause a substitution of asparagine by serine at amino position 1489. This variant has not been reported in the literature but has been reported in ClinVar three times as a variant of uncertain significance (Variation ID: 373598). This variant lies in a critical calcium binding site within a calcium-binding EGF domain; however, since asparagine to serine substitutions in these positions might be tolerated (PMID:31227806) the PM1 criterion has not been used. It is not present in gnomAD v2.1.1 nor v3.1.2 (PM2_supporting; https://gnomad.broadinstitute.org/). Computational prediction tools and conservation analysis are unclear about the predicted impact of this variant (REVEL = 0.556). The constraint z-score for missense variants affecting FBN1 is 5.06 (PP2). Another missense variant at the same position (p.Asn1489Lys) is classified as likely pathogenic (PM5; PMIDs: 20082464, 26621581; 21542060). Due to the insufficient evidence, this variant is classified as of uncertain significance for Marfan syndrome based on the ACMG/AMP criteria applied, as specified by the ClinGen FBN1 VCEP: PM2_supporting, PP2, PM5. LINK:https://erepo.genome.network/evrepo/ui/classification/CA16042872/MONDO:0007947/022

• Frequency: Genomes: not found (cov: 32)
• Consequence: FBN1 NM_000138.5 missense
• Clinical Significance: Uncertain significance reviewed by expert panel U:4
• Conservation: PhyloP100: 8.02
• Publications: 1 publications found

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)

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PM5: For more information check the summary or visit ClinGen Evidence Repository.
• PP2: For more information check the summary or visit ClinGen Evidence Repository.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000138.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FBN1	NM_000138.5	MANE Select	c.4466A>G	p.Asn1489Ser	missense	Exon 37 of 66	NP_000129.3
	FBN1	NM_001406716.1		c.4466A>G	p.Asn1489Ser	missense	Exon 36 of 65	NP_001393645.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FBN1	ENST00000316623.10	TSL:1 MANE Select	c.4466A>G	p.Asn1489Ser	missense	Exon 37 of 66	ENSP00000325527.5
	FBN1	ENST00000559133.6	TSL:1	n.4466A>G		non_coding_transcript_exon	Exon 37 of 67	ENSP00000453958.2
	FBN1	ENST00000537463.6	TSL:5	n.*229A>G		non_coding_transcript_exon	Exon 12 of 31	ENSP00000440294.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
-	1	-	Marfan syndrome (1)
-	1	-	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 (1)
-	1	-	Marfan syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection (1)
-	1	-	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.20
BayesDel_addAF	Uncertain	0.12	D
BayesDel_noAF	Uncertain	-0.060
CADD	Uncertain	24
DANN	Uncertain	1.0
Eigen	Uncertain	0.35
Eigen_PC	Uncertain	0.47
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D
M_CAP	Uncertain	0.23	D
MetaRNN	Pathogenic	0.80	D
MetaSVM	Uncertain	0.50	D
PhyloP100		8.0
PrimateAI	Uncertain	0.58	T
PROVEAN	Uncertain	-2.9	D
REVEL	Uncertain	0.56
Sift	Uncertain	0.0070	D
Sift4G	Uncertain	0.014	D
Vest4		0.72
MutPred		0.66		Gain of disorder (P = 0.087)
MVP		0.93
MPC		0.60
ClinPred		0.95	D
GERP RS		5.6
Mutation Taster		=57/43	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

Other links and lift over

dbSNP: rs1057518501; hg19: chr15-48760725;