rs137854466

Variant names:

• chr15-48411280-G-A
• rs137854466
• NM_000138.5:c.8326C>T

Your query was ambiguous. Multiple possible variants found:

• chr15-48411280-G-A
• chr15-48411280-G-C

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PP4 PM2_Supporting PS3 PS4 PP1_Strong PVS1_Strong

This summary comes from the ClinGen Evidence Repository: The NM_00138 c.8326C>T, is a nonsense variant in FBN1 that occurs in the last exon of the gene and is not expected to undergo nonsense-mediated decay but is expected to disrupt the last 96 amino acids of the protein. Premature terminations in the C-terminus are considered to be deleterious (PVS1_Strong; PMID 24982166, 12161601, 7911051, 21034599). In an in-vitro microfibril assay, this variant was reported to result in intracellular retention of the protein (PMID 24982166; PS3). This variant was found in a proband with aortic aneurysm and dissection, ectopia lentis, and skeletal features, who met revised Ghent criteria, which is a highly specific phenotype for Marfan syndrome (MFS) (Internal lab data; PP4). This variant has been reported 10 times in ClinVar, nine as pathogenic and once as likely pathogenic (Variation ID: 16439). Several other probands with a clinical diagnosis of Marfan syndrome and/or clinical features of Marfan syndrome carry the same variant (internal lab data, PMID 9338581, 31098894, 31730815, 33059708, 25907466, 19293843, 34916231; PS4). In one individual with aortic dissection and myopia, this variant was reported to be de novo without confirmation of parental relationships (PMID 31098894; 0.25 points). In two families with MFS, this variant was found to segregate with disease in five affected family members (internal lab data; PP1_Strong). This variant is present in in 10/24982 (0.04%) of alleles tested from the Finnish population in gnomAD and did not pass the quality control criteria in the genome subset (PM2_Sup; https://gnomad.broadinstitute.org/ v2.1.1). In summary, this variant meets criteria to be classified as pathogenic for Marfan syndrome based on the ACMG/AMP criteria applied, as specified by the ClinGen FBN1 VCEP: PVS1_Strong, PS4, PS3, PP1_Strong, PM2_Sup, PP4 LINK:https://erepo.genome.network/evrepo/ui/classification/CA017692/MONDO:0007947/022

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: FBN1 NM_000138.5 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:12 U:1
• Conservation: PhyloP100: 8.16
• Publications: 8 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):

• Marfan syndrome

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P, ClinGen, Orphanet, Genomics England PanelApp
• familial thoracic aortic aneurysm and aortic dissection

  Inheritance: Unknown, AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• Acromicric dysplasia

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet
• progeroid and marfanoid aspect-lipodystrophy syndrome

  Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet, Labcorp Genetics (formerly Invitae)
• stiff skin syndrome

  Inheritance: AD Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• 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: Unknown, AD Classification: LIMITED, NO_KNOWN Submitted by: Labcorp Genetics (formerly Invitae), ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: For more information check the summary or visit ClinGen Evidence Repository.
• PS3: For more information check the summary or visit ClinGen Evidence Repository.
• PS4: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PP1: For more information check the summary or visit ClinGen Evidence Repository.
• PP4: 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.8326C>T	p.Arg2776*	stop_gained	Exon 66 of 66	NP_000129.3
	FBN1	NM_001406716.1		c.8326C>T	p.Arg2776*	stop_gained	Exon 65 of 65	NP_001393645.1	P35555

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FBN1	ENST00000316623.10	TSL:1 MANE Select	c.8326C>T	p.Arg2776*	stop_gained	Exon 66 of 66	ENSP00000325527.5	P35555
	FBN1	ENST00000559133.6	TSL:1	n.*1134C>T		non_coding_transcript_exon	Exon 67 of 67	ENSP00000453958.2	H0YND0
	FBN1	ENST00000559133.6	TSL:1	n.*1134C>T		3_prime_UTR	Exon 67 of 67	ENSP00000453958.2	H0YND0

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152114 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.0000944

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000398 AC: 10 AN: 251286 AF XY: 0.0000737

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 FIN exome AF: 0.000418

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.0000123 AC: 18 AN: 1461668 Hom.: 0 Cov.: 31 AF XY: 0.0000248 AC XY: 18 AN XY: 727076

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.000319 AC: 17 AN: 53282

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111950

Other (OTH) AF: 0.0000166 AC: 1 AN: 60392

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152232 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74430

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41546

American (AMR) AF: 0.00 AC: 0 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5190

South Asian (SAS) AF: 0.00 AC: 0 AN: 4826

European-Finnish (FIN) AF: 0.0000944 AC: 1 AN: 10592

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68008

Other (OTH) AF: 0.00 AC: 0 AN: 2116

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
7	1	-	Marfan syndrome (8)
2	-	-	not provided (2)
1	-	-	Familial thoracic aortic aneurysm and aortic dissection (1)
1	-	-	Isolated thoracic aortic aneurysm (1)
1	-	-	Marfan syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	50
DANN	Uncertain	1.0
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		8.2
Vest4		0.85
GERP RS		5.5
Mutation Taster		=16/184	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs137854466; hg19: chr15-48703477; COSMIC: COSV57312804;