chr15-48644601-T-C

Variant names:

• chr15-48644601-T-C
• rs397515760
• ENST00000560355.1:c.*1A>G

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_Strong BP6

The ENST00000560355.1(FBN1):​c.*1A>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000013 in 1,461,778 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000013 (0 hom.)
• Consequence: FBN1 ENST00000560355.1 3_prime_UTR
• Scores: Splicing: ADA: 0.0001840
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1
• Conservation: PhyloP100: -1.01
• Publications: 0 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: Likely_benign. The variant received -5 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.73).
• BP6: Variant 15-48644601-T-C is Benign according to our data. Variant chr15-48644601-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 42289.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FBN1	NM_000138.5	c.164+5A>G		splice_region_variant, intron_variant	Intron 2 of 65	ENST00000316623.10	NP_000129.3
FBN1	NM_001406716.1	c.164+5A>G		splice_region_variant, intron_variant	Intron 1 of 64		NP_001393645.1
FBN1	NM_001406717.1	c.164+5A>G		splice_region_variant, intron_variant	Intron 2 of 8		NP_001393646.1
FBN1	NM_001406718.1	c.164+5A>G		splice_region_variant, intron_variant	Intron 2 of 2		NP_001393647.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FBN1	ENST00000316623.10	c.164+5A>G		splice_region_variant, intron_variant	Intron 2 of 65	1	NM_000138.5	ENSP00000325527.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.0000278 AC: 7 AN: 251348 AF XY: 0.0000294

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: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000130 AC: 19 AN: 1461778 Hom.: 0 Cov.: 30 AF XY: 0.0000151 AC XY: 11 AN XY: 727190

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: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.000197 AC: 17 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53344

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111986

Other (OTH) AF: 0.0000331 AC: 2 AN: 60390

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not specified Uncertain:1

Mar 04, 2008

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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

Dec 06, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 42289). This variant has been observed in individual(s) with clinical symptoms suggestive of Marfan syndrome, Loeys-Dietz syndrome, or thoracic aortic aneurysm and dissection (PMID: 24793577). This variant is present in population databases (rs397515760, gnomAD 0.02%). This sequence change falls in intron 2 of the FBN1 gene. It does not directly change the encoded amino acid sequence of the FBN1 protein. It affects a nucleotide within the consensus splice site. -

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

Oct 31, 2018

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Familial thoracic aortic aneurysm and aortic dissection Benign:1

Nov 08, 2018

Color Diagnostics, LLC DBA Color Health

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.73
CADD	Benign	8.8
DANN	Benign	0.83
PhyloP100		-1.0
Mutation Taster		=74/26	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00018
dbscSNV1_RF	Benign	0.070
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: rs397515760; hg19: chr15-48936798;