NM_001999.4:c.1734G>C

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 2P and 9B. PP3_ModerateBP6BS1BS2

The NM_001999.4(FBN2):​c.1734G>C​(p.Glu578Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000787 in 1,613,166 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 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000084 ( 0 hom. )

Consequence

FBN2
NM_001999.4 missense

Scores

8
9
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:2

Conservation

PhyloP100: 0.659

Publications

5 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: Benign. The variant received -7 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.906
BP6
Variant 5-128377867-C-G is Benign according to our data. Variant chr5-128377867-C-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 458736.
BS1
Variant frequency is greater than expected in population mid. GnomAdExome4 allele frequency = 0.0000842 (123/1461036) while in subpopulation MID AF = 0.00174 (10/5762). AF 95% confidence interval is 0.000941. There are 0 homozygotes in GnomAdExome4. There are 67 alleles in the male GnomAdExome4 subpopulation. Median coverage is 31. This position passed quality control check.
BS2
High AC in GnomAdExome4 at 123 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
FBN2NM_001999.4 linkc.1734G>C p.Glu578Asp missense_variant Exon 13 of 65 ENST00000262464.9 NP_001990.2 P35556-1
FBN2XM_017009228.3 linkc.1581G>C p.Glu527Asp missense_variant Exon 12 of 64 XP_016864717.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
FBN2ENST00000262464.9 linkc.1734G>C p.Glu578Asp missense_variant Exon 13 of 65 1 NM_001999.4 ENSP00000262464.4 P35556-1
FBN2ENST00000508989.5 linkc.1635G>C p.Glu545Asp missense_variant Exon 12 of 33 2 ENSP00000425596.1 D6RJI3
FBN2ENST00000511489.1 linkn.-46G>C upstream_gene_variant 3

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152130
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000478
AC:
12
AN:
251010
AF XY:
0.0000663
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000441
Gnomad OTH exome
AF:
0.000327
GnomAD4 exome
AF:
0.0000842
AC:
123
AN:
1461036
Hom.:
0
Cov.:
31
AF XY:
0.0000922
AC XY:
67
AN XY:
726864
show subpopulations
African (AFR)
AF:
0.000179
AC:
6
AN:
33436
American (AMR)
AF:
0.0000448
AC:
2
AN:
44680
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26110
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39682
South Asian (SAS)
AF:
0.000104
AC:
9
AN:
86244
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53404
Middle Eastern (MID)
AF:
0.00174
AC:
10
AN:
5762
European-Non Finnish (NFE)
AF:
0.0000792
AC:
88
AN:
1111376
Other (OTH)
AF:
0.000133
AC:
8
AN:
60342
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.460
Heterozygous variant carriers
0
7
13
20
26
33
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.0000263
AC:
4
AN:
152130
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74308
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41440
American (AMR)
AF:
0.00
AC:
0
AN:
15252
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10600
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.000113
Hom.:
0
Bravo
AF:
0.0000416
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000247
AC:
3
Asia WGS
AF:
0.000577
AC:
2
AN:
3478
EpiCase
AF:
0.000218
EpiControl
AF:
0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:3Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1
Jan 04, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.E578D variant (also known as c.1734G>C), located in coding exon 13 of the FBN2 gene, results from a G to C substitution at nucleotide position 1734. The glutamic acid at codon 578 is replaced by aspartic acid, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Ehlers-Danlos syndrome Uncertain:1
Jun 10, 2022
Genome Diagnostics Laboratory, The Hospital for Sick Children
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Dec 23, 2020
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, which includes protein predictors and evolutionary conservation, supports a deleterious effect; 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); Reported in ClinVar as a variant of uncertain significance (ClinVar Variant ID# 458736; Landrum et al., 2016) -

not specified Benign:1
Dec 11, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: FBN2 c.1734G>C (p.Glu578Asp) results in a conservative amino acid change located in the EGF-like domain (IPR000742) of the encoded protein sequence. Three of four in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4.8e-05 in 251010 control chromosomes. The observed variant frequency is approximately 38 fold of the estimated maximal expected allele frequency for a pathogenic variant in FBN2 causing Aortopathy phenotype (1.3e-06), strongly suggesting that the variant is benign. To our knowledge, no occurrence of c.1734G>C in individuals affected with Aortopathy and no experimental evidence demonstrating its impact on protein function have been reported. Three submitters have cited clinical-significance assessments for this variant to ClinVar after 2014 and classified this variant as likely benign (n=1) and uncertain significance (n=2). Based on the evidence outlined above, the variant was classified as likely benign. -

Congenital contractural arachnodactyly Benign:1
Jan 12, 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
Pathogenic
0.99
BayesDel_addAF
Uncertain
0.14
D
BayesDel_noAF
Pathogenic
0.22
CADD
Benign
23
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.66
D;.;D;D
Eigen
Uncertain
0.27
Eigen_PC
Benign
0.13
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Uncertain
0.97
D;.;.;D
M_CAP
Pathogenic
0.68
D
MetaRNN
Pathogenic
0.91
D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.0
M;.;M;.
PhyloP100
0.66
PrimateAI
Pathogenic
0.83
D
PROVEAN
Uncertain
-2.8
D;.;D;D
REVEL
Pathogenic
0.89
Sift
Uncertain
0.0050
D;.;D;D
Sift4G
Uncertain
0.020
.;.;.;D
Polyphen
0.98
D;.;D;D
Vest4
0.68
MutPred
0.85
Gain of relative solvent accessibility (P = 0.1066);.;Gain of relative solvent accessibility (P = 0.1066);.;
MVP
0.89
MPC
0.82
ClinPred
0.76
D
GERP RS
1.4
Varity_R
0.48
gMVP
0.89
Mutation Taster
=72/28
polymorphism

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

Other links and lift over

dbSNP: rs371046485; hg19: chr5-127713560; COSMIC: COSV52535712; COSMIC: COSV52535712; API