NM_001999.4:c.2507C>T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 1P and 4B. PP3BS2

The NM_001999.4(FBN2):​c.2507C>T​(p.Thr836Met) variant causes a missense change. The variant allele was found at a frequency of 0.0000123 in 1,461,792 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T836S) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

FBN2
NM_001999.4 missense

Scores

2
12
5

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 4.02

Publications

1 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)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.819
BS2
High AC in GnomAdExome4 at 18 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
FBN2NM_001999.4 linkc.2507C>T p.Thr836Met missense_variant Exon 19 of 65 ENST00000262464.9 NP_001990.2
FBN2XM_017009228.3 linkc.2354C>T p.Thr785Met missense_variant Exon 18 of 64 XP_016864717.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
FBN2ENST00000262464.9 linkc.2507C>T p.Thr836Met missense_variant Exon 19 of 65 1 NM_001999.4 ENSP00000262464.4
FBN2ENST00000508989.5 linkc.2408C>T p.Thr803Met missense_variant Exon 18 of 33 2 ENSP00000425596.1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251454
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000123
AC:
18
AN:
1461792
Hom.:
0
Cov.:
31
AF XY:
0.0000138
AC XY:
10
AN XY:
727198
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33478
American (AMR)
AF:
0.0000447
AC:
2
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39690
South Asian (SAS)
AF:
0.0000812
AC:
7
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000540
AC:
6
AN:
1111930
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60390
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.444
Heterozygous variant carriers
0
1
3
4
6
7
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:1
Jul 27, 2022
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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; Observed in an individual with Usher syndrome who also harbored a second FBN2 variant and a MYH14 variant (Bahena et al., 2022); 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); This variant is associated with the following publications: (PMID: 34148116, 19006240, 18767143) -

Congenital contractural arachnodactyly Uncertain:1
Apr 25, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 836 of the FBN2 protein (p.Thr836Met). This variant is present in population databases (no rsID available, gnomAD 0.003%). 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: 561298). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt FBN2 protein function with a negative predictive value of 80%. 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. -

Connective tissue disorder Uncertain:1
Jun 01, 2018
Center for Human Genetics, Inc, Center for Human Genetics, Inc
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.10
BayesDel_addAF
Uncertain
0.084
D
BayesDel_noAF
Uncertain
-0.030
CADD
Pathogenic
27
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.75
D;.;D;D
Eigen
Uncertain
0.54
Eigen_PC
Uncertain
0.54
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Benign
0.66
T;.;.;T
M_CAP
Uncertain
0.13
D
MetaRNN
Pathogenic
0.82
D;D;D;D
MetaSVM
Uncertain
0.76
D
MutationAssessor
Benign
1.7
L;.;L;.
PhyloP100
4.0
PrimateAI
Benign
0.42
T
PROVEAN
Uncertain
-3.1
D;.;D;D
REVEL
Uncertain
0.63
Sift
Uncertain
0.024
D;.;D;D
Sift4G
Uncertain
0.020
.;.;.;D
Polyphen
0.91
P;.;P;D
Vest4
0.53
MutPred
0.53
Loss of glycosylation at T836 (P = 0.0115);.;Loss of glycosylation at T836 (P = 0.0115);.;
MVP
0.47
MPC
0.80
ClinPred
0.96
D
GERP RS
4.7
Varity_R
0.18
gMVP
0.48
Mutation Taster
=56/44
polymorphism

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

Other links and lift over

dbSNP: rs957177447; hg19: chr5-127697463; COSMIC: COSV52518254; COSMIC: COSV52518254; API