rs1554116412

Positions:

• chr5-128272099-CC-TT

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_001999.4(FBN2):​c.7859_7860delinsAA​(p.Gly2620Glu) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★). Another nucleotide change resulting in same amino acid change has been previously reported as Uncertain significancein ClinVar. Synonymous variant affecting the same amino acid position (i.e. G2620G) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 31)
• Consequence: FBN2 NM_001999.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 4.12

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, FBN2

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FBN2	NM_001999.4	c.7859_7860delinsAA	p.Gly2620Glu	missense_variant	62/65	ENST00000262464.9
FBN2	XM_017009228.3	c.7706_7707delinsAA	p.Gly2569Glu	missense_variant	61/64

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FBN2	ENST00000262464.9	c.7859_7860delinsAA	p.Gly2620Glu	missense_variant	62/65	1	NM_001999.4	P1
FBN2	ENST00000703783.1	n.4643_4644delinsAA		non_coding_transcript_exon_variant	37/38
FBN2	ENST00000703784.1	n.26_27delinsAA		non_coding_transcript_exon_variant	2/2
FBN2	ENST00000703782.1			upstream_gene_variant

Frequencies

GnomAD3 genomes Cov.: 31

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 12, 2020

The c.7859_7860delGGinsAA variant (also known as p.G2620E), located in coding exon 62 of the FBN2 gene, results from an in-frame deletion of GG and insertion of AA at nucleotide positions 7859 to 7860. This results in the substitution of the glycine residue for a glutamic acid residue at codon 2620, an amino acid with similar properties, and is located in the cbEGF-like #42 domain. This amino acid substitution (p.G2620E, described as c.7859G>A) was reported in a severe scoliosis cohort; however, clinical details were limited (Buchan JG et al. Hum Mol Genet, 2014 Oct;23:5271-82). This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive (Choi Y et al. PLoS ONE. 2012; 7(10):e46688). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Congenital contractural arachnodactyly Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Nov 19, 2023

This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 2620 of the FBN2 protein (p.Gly2620Glu). This variant is present in population databases (no rsID available, gnomAD 0.002%). This variant has not been reported in the literature in individuals affected with FBN2-related conditions. ClinVar contains an entry for this variant (Variation ID: 458780). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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 v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1554116412; hg19: chr5-127607791;