NM_001999.4:c.6833C>T

Variant names:

Variant summary

Our verdict is Benign. The variant received -11 ACMG points: 0P and 11B. BP4_ModerateBP6BS1BS2

The NM_001999.4(FBN2):c.6833C>T(p.Thr2278Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000133 in 1,613,972 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T2278K) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000079 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00014 ( 0 hom. )

Consequence

FBN2
NM_001999.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:1

Conservation

PhyloP100: 1.50

Publications

7 publications found

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 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)

FBN2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -11 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.114136666).

BP6

Variant 5-128287355-G-A is Benign according to our data. Variant chr5-128287355-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 225102.

BS1

Variant frequency is greater than expected in population eas. GnomAd4 allele frequency = 0.0000788 (12/152270) while in subpopulation EAS AF = 0.00174 (9/5170). AF 95% confidence interval is 0.000908. There are 0 homozygotes in GnomAd4. There are 5 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

BS2

High AC in GnomAd4 at 12 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FBN2	NM_001999.4 link	c.6833C>T	p.Thr2278Met	missense_variant	Exon 54 of 65	ENST00000262464.9	NP_001990.2	P35556-1
FBN2	XM_017009228.3 link	c.6680C>T	p.Thr2227Met	missense_variant	Exon 53 of 64		XP_016864717.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FBN2	ENST00000262464.9 link	c.6833C>T	p.Thr2278Met	missense_variant	Exon 54 of 65	1	NM_001999.4	ENSP00000262464.4		P35556-1
FBN2	ENST00000703783.1 link	n.3617C>T		non_coding_transcript_exon_variant	Exon 29 of 38

Frequencies

GnomAD3 genomes

AF:

0.0000789

AC:

AN:

152152

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

Gnomad ASJ

AF:

0.000288

Gnomad EAS

AF:

0.00174

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000955

AC:

AN:

251276

AF XY:

0.000118

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00103

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000138

AC:

202

AN:

1461702

Hom.:

Cov.:

AF XY:

0.000132

AC XY:

AN XY:

727168

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33468

American (AMR)

AF:

0.0000224

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.00423

AC:

168

AN:

39692

South Asian (SAS)

AF:

0.000128

AC:

AN:

86250

European-Finnish (FIN)

AF:

0.0000187

AC:

AN:

53408

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.0000108

AC:

AN:

1111870

Other (OTH)

AF:

0.000132

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.473

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000788

AC:

AN:

152270

Hom.:

Cov.:

AF XY:

0.0000672

AC XY:

AN XY:

74452

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41566

American (AMR)

AF:

0.0000654

AC:

AN:

15294

Ashkenazi Jewish (ASJ)

AF:

0.000288

AC:

AN:

3468

East Asian (EAS)

AF:

0.00174

AC:

AN:

5170

South Asian (SAS)

AF:

0.00

AC:

AN:

4818

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10612

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68022

Other (OTH)

AF:

0.00

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.538

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000129

Hom.:

Bravo

AF:

0.0000793

ExAC

AF:

0.0000906

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Nov 10, 2014

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Lines of evidence used in support of classification: UNCERTAIN: Alteration(s) of Uncertain Clinical Significance Detected -

not provided

Uncertain:1

Apr 28, 2017

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

A variant of uncertain significance has been identified in the FBN2 gene. The T2278M variant has not been published as pathogenic or been reported as benign to our knowledge. This variant is observed in 10/8644 (0.1%) alleles from individuals of East Asian ancestry in the Exome Aggregation Consortium (ExAC) datset (Lek et al., 2016; Exome Variant Server). This substitution occurs at a position that is conserved in mammals and in silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. Furthermore, while the T2278M variant is located within a calcium-binding EGF-like domain of the FBN2 gene, it does not affect a Cysteine residue in this domain. Cysteine substitutions in the calcium-binding EGF-like domains represent the majority of pathogenic missense changes associated with congenital arachnodactyly (Collod-Beroud et al., 2003; FrÃ©dÃ©ric et al., 2009). Nevertheless, the T2278M variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. -

Congenital contractural arachnodactyly

Benign:1

Jan 20, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.092

BayesDel_addAF

Benign

-0.24

BayesDel_noAF

Benign

-0.17

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.54

D;.;D

Eigen

Benign

0.11

Eigen_PC

Uncertain

0.25

FATHMM_MKL

Uncertain

0.88

LIST_S2

Uncertain

0.91

D;.;.

M_CAP

Benign

0.018

MetaRNN

Benign

0.11

T;T;T

MetaSVM

Uncertain

0.16

MutationAssessor

Benign

1.9

L;.;L

PhyloP100

1.5

PrimateAI

Benign

0.44

PROVEAN

Benign

-1.9

N;.;N

REVEL

Uncertain

0.37

Sift

Benign

0.14

T;.;T

Polyphen

0.47

P;.;P

Vest4

0.21

MVP

0.30

MPC

0.68

ClinPred

0.072

GERP RS

5.3

Varity_R

0.067

gMVP

0.70

Mutation Taster

=62/38

polymorphism

(source)

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over