rs1348701377

Positions:

• chr5-128339053-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 7P and 1B. PM2 PP2 PP3_Strong BP6

The NM_001999.4(FBN2):​c.3352G>A​(p.Glu1118Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,686 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: FBN2 NM_001999.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 7.90

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 Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), FBN2. . Gene score misZ 1.5491 (greater than the threshold 3.09). Trascript score misZ 3.2752 (greater than threshold 3.09). GenCC has associacion of gene with familial thoracic aortic aneurysm and aortic dissection, carpal tunnel syndrome, macular degeneration, early-onset, congenital contractural arachnodactyly.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.987
• BP6: Variant 5-128339053-C-T is Benign according to our data. Variant chr5-128339053-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 458757.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FBN2	NM_001999.4	c.3352G>A	p.Glu1118Lys	missense_variant	26/65	ENST00000262464.9	NP_001990.2
FBN2	XM_017009228.3	c.3199G>A	p.Glu1067Lys	missense_variant	25/64		XP_016864717.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FBN2	ENST00000262464.9	c.3352G>A	p.Glu1118Lys	missense_variant	26/65	1	NM_001999.4	ENSP00000262464	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251280 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135812

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad SAS 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: 0.00000205 AC: 3 AN: 1461686 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727152

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Dec 30, 2022

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Although located in a calcium-binding EGF-like domain of the FBN2 gene, it does not substitute or introduce a cysteine residue (Callewaert et al., 2009; Frederic et al., 2009); Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 31506931, 19006240, 18767143) -

Congenital contractural arachnodactyly Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 22, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	28
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.93	D;.;D;D
Eigen	Pathogenic	0.95
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;.;.;D
M_CAP	Pathogenic	0.47	D
MetaRNN	Pathogenic	0.99	D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.1	M;.;M;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.83	D
PROVEAN	Uncertain	-3.6	D;.;D;D
REVEL	Pathogenic	0.94
Sift	Benign	0.035	D;.;D;D
Sift4G	Uncertain	0.044	.;.;.;D
Polyphen		1.0	D;.;D;D
Vest4		0.96
MutPred		0.91		Gain of methylation at E1118 (P = 0.0031);.;Gain of methylation at E1118 (P = 0.0031);.;
MVP		0.97
MPC		0.92
ClinPred		0.98	D
GERP RS		5.1
Varity_R		0.75
gMVP		0.97

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

Publications

LitVar

Other links and lift over

dbSNP: rs1348701377; hg19: chr5-127674745; COSMIC: COSV52503780;