5-128349358-C-T

Variant names:

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 1P and 5B. PP3BS1_SupportingBS2

The NM_001999.4(FBN2):c.2978G>A(p.Arg993His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000613 in 1,614,072 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000072 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000060 ( 0 hom. )

Consequence

FBN2
NM_001999.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:1

Conservation

PhyloP100: 7.84

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.78

BS1

Variant frequency is greater than expected in population sas. gnomad4_exome allele frequency = 0.0000602 (88/1461820) while in subpopulation SAS AF= 0.00051 (44/86256). AF 95% confidence interval is 0.000391. There are 0 homozygotes in gnomad4_exome. There are 54 alleles in male gnomad4_exome subpopulation. Median coverage is 31. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

BS2

High AC in GnomAd4 at 11 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FBN2	NM_001999.4 link	c.2978G>A	p.Arg993His	missense_variant	Exon 23 of 65	ENST00000262464.9	NP_001990.2	P35556-1
FBN2	XM_017009228.3 link	c.2825G>A	p.Arg942His	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 link	c.2978G>A	p.Arg993His	missense_variant	Exon 23 of 65	1	NM_001999.4	ENSP00000262464.4		P35556-1
FBN2	ENST00000508989.5 link	c.2879G>A	p.Arg960His	missense_variant	Exon 22 of 33	2		ENSP00000425596.1		D6RJI3

Frequencies

GnomAD3 genomes

AF:

0.0000723

AC:

AN:

152134

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000966

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000915

AC:

AN:

251400

Hom.:

AF XY:

0.000140

AC XY:

AN XY:

135880

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.0000867

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000392

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000616

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000602

AC:

AN:

1461820

Hom.:

Cov.:

AF XY:

0.0000743

AC XY:

AN XY:

727214

show subpopulations

Gnomad4 AFR exome

AF:

0.000269

Gnomad4 AMR exome

AF:

0.0000671

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000510

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000225

Gnomad4 OTH exome

AF:

0.000116

GnomAD4 genome

AF:

0.0000722

AC:

AN:

152252

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74452

show subpopulations

Gnomad4 AFR

AF:

0.0000963

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.000208

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000599

Hom.:

Bravo

AF:

0.000155

ExAC

AF:

0.0000494

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.000296

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Feb 16, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Has not been previously published as pathogenic or benign to our knowledge; 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 affect a cysteine residue within this domain; cysteine substitutions in the calcium-binding EGF-like domains represent the majority of pathogenic missense changes associated with FBN2-related disorders (Frederic et al., 2009).; This variant is associated with the following publications: (PMID: 18767143) -

May 20, 2021

Mayo Clinic Laboratories, Mayo Clinic

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Familial thoracic aortic aneurysm and aortic dissection

Uncertain:1

Jul 13, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R993H variant (also known as c.2978G>A), located in coding exon 23 of the FBN2 gene, results from a G to A substitution at nucleotide position 2978. The arginine at codon 993 is replaced by histidine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Congenital contractural arachnodactyly

Benign:1

Jun 25, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.28

BayesDel_addAF

Benign

-0.016

BayesDel_noAF

Uncertain

0.060

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.77

D;.;D;D

Eigen

Uncertain

0.61

Eigen_PC

Uncertain

0.56

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.95

D;.;.;D

M_CAP

Benign

0.083

MetaRNN

Pathogenic

0.78

D;D;D;D

MetaSVM

Uncertain

0.76

MutationAssessor

Benign

0.82

L;.;L;.

PrimateAI

Uncertain

0.62

PROVEAN

Uncertain

-3.5

D;.;D;D

REVEL

Pathogenic

0.69

Sift

Uncertain

0.0040

D;.;D;D

Sift4G

Benign

0.46

.;.;.;T

Polyphen

1.0

D;.;D;D

Vest4

0.70

MVP

0.80

MPC

0.87

ClinPred

0.55

GERP RS

4.0

Varity_R

0.40

gMVP

0.59

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.070

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over