chr5-128349445-C-T

Variant names:

• chr5-128349445-C-T
• rs1554124089
• NM_001999.4:c.2891G>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_001999.4(FBN2):​c.2891G>A​(p.Gly964Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G964C) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: FBN2 NM_001999.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.84
• 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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FBN2	NM_001999.4	c.2891G>A	p.Gly964Asp	missense_variant	Exon 23 of 65	ENST00000262464.9	NP_001990.2
FBN2	XM_017009228.3	c.2738G>A	p.Gly913Asp	missense_variant	Exon 22 of 64		XP_016864717.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FBN2	ENST00000262464.9	c.2891G>A	p.Gly964Asp	missense_variant	Exon 23 of 65	1	NM_001999.4	ENSP00000262464.4
FBN2	ENST00000508989.5	c.2792G>A	p.Gly931Asp	missense_variant	Exon 22 of 33	2		ENSP00000425596.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 34

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

Nov 24, 2017

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. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with FBN2-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glycine with aspartic acid at codon 964 of the FBN2 protein (p.Gly964Asp). The glycine residue is moderately conserved and there is a moderate physicochemical difference between glycine and aspartic acid. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.21
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.24
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.76	D;.;D;D
Eigen	Uncertain	0.61
Eigen_PC	Uncertain	0.61
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Pathogenic	0.98	D;.;.;D
M_CAP	Uncertain	0.17	D
MetaRNN	Uncertain	0.74	D;D;D;D
MetaSVM	Uncertain	0.60	D
MutationAssessor	Benign	0.81	L;.;L;.
PhyloP100		7.8
PrimateAI	Pathogenic	0.85	D
PROVEAN	Pathogenic	-5.1	D;.;D;D
REVEL	Pathogenic	0.76
Sift	Benign	0.078	T;.;T;T
Sift4G	Benign	0.17	.;.;.;T
Polyphen		1.0	D;.;D;D
Vest4		0.86
MutPred		0.55		Loss of catalytic residue at C966 (P = 0.0901);.;Loss of catalytic residue at C966 (P = 0.0901);.;
MVP		0.77
MPC		0.84
ClinPred		0.99	D
GERP RS		4.2
Varity_R		0.60
gMVP		0.69
Mutation Taster		=2/98	disease causing

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: rs1554124089; hg19: chr5-127685137;