rs1554120093

Variant names:

• chr5-128309256-G-A
• rs1554120093
• NM_001999.4:c.5344C>T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001999.4(FBN2):​c.5344C>T​(p.Pro1782Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. P1782P) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: FBN2 NM_001999.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.60
• Publications: 0 publications found

Genes affected

FBN2 (HGNC:3604): (fibrillin 2) The protein encoded by this gene is a component of connective tissue microfibrils and may be involved in elastic fiber assembly. Mutations in this gene cause congenital contractural arachnodactyly. [provided by RefSeq, Jul 2008]

FBN2 Gene-Disease associations (from GenCC):

• congenital contractural arachnodactyly

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: PanelApp Australia, Orphanet, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp
• carpal tunnel syndrome

  Inheritance: AD Classification: LIMITED Submitted by: Franklin by Genoox
• familial thoracic aortic aneurysm and aortic dissection

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• macular degeneration, early-onset

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.863

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001999.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FBN2	NM_001999.4	MANE Select	c.5344C>T	p.Pro1782Ser	missense	Exon 41 of 65	NP_001990.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FBN2	ENST00000262464.9	TSL:1 MANE Select	c.5344C>T	p.Pro1782Ser	missense	Exon 41 of 65	ENSP00000262464.4
	FBN2	ENST00000703783.1		n.2128C>T		non_coding_transcript_exon	Exon 16 of 38
	FBN2	ENST00000703785.1		n.2047C>T		non_coding_transcript_exon	Exon 15 of 27

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital contractural arachnodactyly Uncertain:1

Oct 18, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature in individuals with FBN2-related disease. This sequence change replaces proline with serine at codon 1782 of the FBN2 protein (p.Pro1782Ser). The proline residue is highly conserved and there is a moderate physicochemical difference between proline and serine. This variant is not present in population databases (ExAC no frequency). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.21
BayesDel_addAF	Pathogenic	0.17	D
BayesDel_noAF	Uncertain	0.010
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.77	D
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.67
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Benign	0.81	T
M_CAP	Uncertain	0.12	D
MetaRNN	Pathogenic	0.86	D
MetaSVM	Uncertain	0.78	D
MutationAssessor	Benign	2.0	M
PhyloP100		9.6
PrimateAI	Uncertain	0.70	T
PROVEAN	Pathogenic	-5.8	D
REVEL	Pathogenic	0.68
Sift	Benign	0.045	D
Polyphen		1.0	D
Vest4		0.58
MutPred		0.73		Gain of glycosylation at P1782 (P = 0.0158)
MVP		0.62
MPC		0.83
ClinPred		0.99	D
GERP RS		4.8
Varity_R		0.29
gMVP		0.53
Mutation Taster		=62/38	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: rs1554120093; hg19: chr5-127644948;