rs77493726

Variant summary

Our verdict is Benign. The variant received -18 ACMG points: 0P and 18B. BP4_ModerateBP6_Very_StrongBS1BS2

The NM_001999.4(FBN2):​c.2428+6T>A variant causes a splice region, intron change. The variant allele was found at a frequency of 0.000371 in 1,612,852 control chromosomes in the GnomAD database, including 1 homozygotes. 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 Benign (★★).

Frequency

Genomes: 𝑓 0.0020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00020 ( 1 hom. )

Consequence

FBN2
NM_001999.4 splice_region, intron

Scores

2
Splicing: ADA: 0.4850
2

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:6

Conservation

PhyloP100: 4.22

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 -18 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.3).
BP6
Variant 5-128364594-A-T is Benign according to our data. Variant chr5-128364594-A-T is described in ClinVar as Benign. ClinVar VariationId is 258511.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00205 (312/152338) while in subpopulation AFR AF = 0.00726 (302/41580). AF 95% confidence interval is 0.00659. There are 0 homozygotes in GnomAd4. There are 154 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
BS2
High AC in GnomAd4 at 312 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
FBN2NM_001999.4 linkc.2428+6T>A splice_region_variant, intron_variant Intron 18 of 64 ENST00000262464.9 NP_001990.2 P35556-1
FBN2XM_017009228.3 linkc.2275+6T>A splice_region_variant, intron_variant Intron 17 of 63 XP_016864717.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
FBN2ENST00000262464.9 linkc.2428+6T>A splice_region_variant, intron_variant Intron 18 of 64 1 NM_001999.4 ENSP00000262464.4 P35556-1
FBN2ENST00000508989.5 linkc.2329+6T>A splice_region_variant, intron_variant Intron 17 of 32 2 ENSP00000425596.1 D6RJI3

Frequencies

GnomAD3 genomes
AF:
0.00204
AC:
311
AN:
152220
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00726
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000523
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:
0.0000147
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.000506
AC:
127
AN:
250858
AF XY:
0.000369
show subpopulations
Gnomad AFR exome
AF:
0.00739
Gnomad AMR exome
AF:
0.000116
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000882
Gnomad OTH exome
AF:
0.000327
GnomAD4 exome
AF:
0.000196
AC:
286
AN:
1460514
Hom.:
1
Cov.:
29
AF XY:
0.000168
AC XY:
122
AN XY:
726624
show subpopulations
African (AFR)
AF:
0.00769
AC:
257
AN:
33436
American (AMR)
AF:
0.000157
AC:
7
AN:
44696
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26102
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39598
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86202
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53400
Middle Eastern (MID)
AF:
0.000347
AC:
2
AN:
5760
European-Non Finnish (NFE)
AF:
0.00000270
AC:
3
AN:
1110966
Other (OTH)
AF:
0.000282
AC:
17
AN:
60354
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.473
Heterozygous variant carriers
0
14
28
43
57
71
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
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:
0.00205
AC:
312
AN:
152338
Hom.:
0
Cov.:
33
AF XY:
0.00207
AC XY:
154
AN XY:
74500
show subpopulations
African (AFR)
AF:
0.00726
AC:
302
AN:
41580
American (AMR)
AF:
0.000523
AC:
8
AN:
15310
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68028
Other (OTH)
AF:
0.000473
AC:
1
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.503
Heterozygous variant carriers
0
18
36
54
72
90
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.000514
Hom.:
0
Bravo
AF:
0.00226
Asia WGS
AF:
0.000578
AC:
2
AN:
3476
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Benign
Submissions summary: Benign:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:3
May 28, 2025
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: FBN2 c.2428+6T>A alters a conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Consensus agreement among computation tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.00051 in 250858 control chromosomes, predominantly at a frequency of 0.0074 within the African or African-American subpopulation in the gnomAD database. The observed variant frequency within African or African-American control individuals in the gnomAD database exceeds the estimated maximal expected allele frequency for a pathogenic variant in FBN2 causing Nonsyndromic Heritable Thoracic Aortic Aneurysms And Dissections phenotype. To our knowledge, no occurrence of c.2428+6T>A in individuals affected with Nonsyndromic Heritable Thoracic Aortic Aneurysms And Dissections and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 258511). Based on the evidence outlined above, the variant was classified as benign. -

-
PreventionGenetics, part of Exact Sciences
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Aug 07, 2015
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Congenital contractural arachnodactyly Benign:2
Jan 31, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

not provided Benign:1
Jul 30, 2021
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.30
CADD
Benign
20
DANN
Benign
0.93
PhyloP100
4.2

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.49
dbscSNV1_RF
Benign
0.42
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: rs77493726; hg19: chr5-127700287; API