rs749376421

Variant summary

Our verdict is Benign. The variant received -13 ACMG points: 0P and 13B. BP4_StrongBP6BS1BS2

The NM_001999.4(FBN2):​c.7012+6C>T variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000756 in 1,613,782 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00031 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000051 ( 0 hom. )

Consequence

FBN2
NM_001999.4 splice_region, intron

Scores

2
Splicing: ADA: 0.00002696
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:5

Conservation

PhyloP100: -1.93

Publications

0 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 -13 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.64).
BP6
Variant 5-128286712-G-A is Benign according to our data. Variant chr5-128286712-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 458777.
BS1
Variant frequency is greater than expected in population amr. GnomAd4 allele frequency = 0.000309 (47/152146) while in subpopulation AMR AF = 0.00275 (42/15276). AF 95% confidence interval is 0.00209. There are 0 homozygotes in GnomAd4. There are 25 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
BS2
High AC in GnomAd4 at 47 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
FBN2NM_001999.4 linkc.7012+6C>T splice_region_variant, intron_variant Intron 55 of 64 ENST00000262464.9 NP_001990.2 P35556-1
FBN2XM_017009228.3 linkc.6859+6C>T splice_region_variant, intron_variant Intron 54 of 63 XP_016864717.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
FBN2ENST00000262464.9 linkc.7012+6C>T splice_region_variant, intron_variant Intron 55 of 64 1 NM_001999.4 ENSP00000262464.4 P35556-1
FBN2ENST00000703783.1 linkn.3796+6C>T splice_region_variant, intron_variant Intron 30 of 37

Frequencies

GnomAD3 genomes
AF:
0.000309
AC:
47
AN:
152146
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00275
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:
0.0000588
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.0000994
AC:
25
AN:
251384
AF XY:
0.0000957
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000347
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000791
Gnomad OTH exome
AF:
0.000489
GnomAD4 exome
AF:
0.0000513
AC:
75
AN:
1461636
Hom.:
0
Cov.:
32
AF XY:
0.0000468
AC XY:
34
AN XY:
727124
show subpopulations
African (AFR)
AF:
0.0000598
AC:
2
AN:
33472
American (AMR)
AF:
0.000403
AC:
18
AN:
44716
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39686
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86246
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53412
Middle Eastern (MID)
AF:
0.000694
AC:
4
AN:
5766
European-Non Finnish (NFE)
AF:
0.0000387
AC:
43
AN:
1111832
Other (OTH)
AF:
0.0000828
AC:
5
AN:
60376
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.455
Heterozygous variant carriers
0
6
11
17
22
28
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
AF:
0.000309
AC:
47
AN:
152146
Hom.:
0
Cov.:
33
AF XY:
0.000336
AC XY:
25
AN XY:
74320
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41410
American (AMR)
AF:
0.00275
AC:
42
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000588
AC:
4
AN:
68028
Other (OTH)
AF:
0.000478
AC:
1
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.508
Heterozygous variant carriers
0
3
6
10
13
16
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:
0.000623
EpiCase
AF:
0.0000545
EpiControl
AF:
0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:5
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Benign:2
Jun 30, 2021
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Aug 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

FBN2: BP4, BS1 -

Congenital contractural arachnodactyly Uncertain:1
Dec 23, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change falls in intron 55 of the FBN2 gene. It does not directly change the encoded amino acid sequence of the FBN2 protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs749376421, gnomAD 0.03%), and has an allele count higher than expected for a pathogenic variant. 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: 458777). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. 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. -

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

- -

FBN2-related disorder Benign:1
May 24, 2024
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Congenital contractural arachnodactyly;C4015286:Macular degeneration, early-onset Benign:1
-
Center for Genomics, Ann and Robert H. Lurie Children's Hospital of Chicago
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant has not been reported in the literature but is present in the Genome Aggregation Database (Highest MAF: 0.3% [42/15276] https://gnomad.broadinstitute.org/variant/5-128286712-G-A?dataset=gnomad_r3) and in ClinVar (Variation ID: 458777). Although this variant occurs in the splice region, computational prediction tools do not suggest that it alters splicing. However, further studies are needed to understand its impact. In summary, data on this variant suggests that this variant does not cause disease but requires further evidence. Therefore, this variant is classified as likely benign. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.64
CADD
Benign
5.8
DANN
Benign
0.48
PhyloP100
-1.9
Mutation Taster
=89/11
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.000027
dbscSNV1_RF
Benign
0.014
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: rs749376421; hg19: chr5-127622404; API