15-48460258-C-T

Variant names:

• chr15-48460258-C-T
• rs387906623
• NM_000138.5:c.5284G>A

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PS3 PM1 PM2 PM5 PP2 PP5_Very_Strong

The NM_000138.5(FBN1):​c.5284G>A​(p.Gly1762Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000657 in 152,192 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV000742920: Functional analysis by Jensen et al. (2015) demonstrated that the p.G1762S alteration resulted in normal or near normal protein secretion, consistent with other alterations associated with geleophysic dysplasia.". Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G1762V) has been classified as Likely pathogenic. The gene FBN1 is included in the ClinGen Criteria Specification Registry.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
• Consequence: FBN1 NM_000138.5 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:13
• Conservation: PhyloP100: 5.68
• Publications: 16 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

Specifications for FBN1 are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Pathogenic. The variant received 19 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV000742920: Functional analysis by Jensen et al. (2015) demonstrated that the p.G1762S alteration resulted in normal or near normal protein secretion, consistent with other alterations associated with geleophysic dysplasia.
• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 15 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 chr15-48460257-C-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 392910.
• PP2: Missense variant in the FBN1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 1311 curated pathogenic missense variants (we use a threshold of 10). The gene has 112 curated benign missense variants. Gene score misZ: 5.0644 (above the threshold of 3.09). Trascript score misZ: 8.1787 (above the threshold of 3.09). GenCC associations: The gene is linked to Weill-Marchesani syndrome 2, dominant, Acromicric dysplasia, isolated ectopia lentis, progeroid and marfanoid aspect-lipodystrophy syndrome, Marfan syndrome, stiff skin syndrome, Shprintzen-Goldberg syndrome, familial thoracic aortic aneurysm and aortic dissection, ectopia lentis 1, isolated, autosomal dominant, Weill-Marchesani syndrome, neonatal Marfan syndrome, geleophysic dysplasia.
• PP5: Variant 15-48460258-C-T is Pathogenic according to our data. Variant chr15-48460258-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 29697.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

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.5284G>A	p.Gly1762Ser	missense	Exon 43 of 66	NP_000129.3
	FBN1	NM_001406716.1		c.5284G>A	p.Gly1762Ser	missense	Exon 42 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.5284G>A	p.Gly1762Ser	missense	Exon 43 of 66	ENSP00000325527.5	P35555
	FBN1	ENST00000559133.6	TSL:1	n.5284G>A		non_coding_transcript_exon	Exon 43 of 67	ENSP00000453958.2	H0YND0
	FBN1	ENST00000537463.6	TSL:5	n.*1047G>A		non_coding_transcript_exon	Exon 18 of 31	ENSP00000440294.2	F6U495

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152074 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

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: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00 AC: 0 AN: 250546 AF XY: 0.00

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 Cov.: 30

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152192 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74392

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

African (AFR) AF: 0.0000241 AC: 1 AN: 41530

American (AMR) AF: 0.00 AC: 0 AN: 15286

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5180

South Asian (SAS) AF: 0.00 AC: 0 AN: 4816

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10572

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68014

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

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
5	-	-	Geleophysic dysplasia 2 (5)
5	-	-	not provided (5)
1	-	-	Familial thoracic aortic aneurysm and aortic dissection (1)
1	-	-	FBN1-related disorder (1)
1	-	-	Marfan syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.72
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.15
CADD	Pathogenic	28
DANN	Uncertain	1.0
Eigen	Benign	0.18
Eigen_PC	Uncertain	0.26
FATHMM_MKL	Uncertain	0.87	D
LIST_S2	Uncertain	0.95	D
M_CAP	Benign	0.071	D
MetaRNN	Uncertain	0.70	D
MetaSVM	Uncertain	-0.15	T
PhyloP100		5.7
PrimateAI	Pathogenic	0.83	D
PROVEAN	Uncertain	-3.7	D
REVEL	Uncertain	0.61
Sift	Uncertain	0.0080	D
Sift4G	Benign	0.064	T
Vest4		0.63
MutPred		0.56		Loss of catalytic residue at G1762 (P = 0.0635)
MVP		0.86
MPC		0.55
ClinPred		0.99	D
GERP RS		5.2
Mutation Taster		=15/85	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
Splicevardb		1.0
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: rs387906623; hg19: chr15-48752455;