chr15-48508578-G-A

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_StrongBP6BS2

The NM_000138.5(FBN1):​c.1837+4C>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 0.0000428 in 1,613,578 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 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000044 ( 0 hom. )

Consequence

FBN1
NM_000138.5 splice_region, intron

Scores

2
Splicing: ADA: 0.0001315
2

Clinical Significance

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

Conservation

PhyloP100: 0.457
Variant links:
Genes affected
FBN1 (HGNC:3603): (fibrillin 1) This gene encodes a member of the fibrillin family of proteins. The encoded preproprotein is proteolytically processed to generate two proteins including the extracellular matrix component fibrillin-1 and the protein hormone asprosin. Fibrillin-1 is an extracellular matrix glycoprotein that serves as a structural component of calcium-binding microfibrils. These microfibrils provide force-bearing structural support in elastic and nonelastic connective tissue throughout the body. Asprosin, secreted by white adipose tissue, has been shown to regulate glucose homeostasis. Mutations in this gene are associated with Marfan syndrome and the related MASS phenotype, as well as ectopia lentis syndrome, Weill-Marchesani syndrome, Shprintzen-Goldberg syndrome and neonatal progeroid syndrome. [provided by RefSeq, Apr 2016]

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -9 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.75).
BP6
Variant 15-48508578-G-A is Benign according to our data. Variant chr15-48508578-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 406295.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=2, Benign=1}. Variant chr15-48508578-G-A is described in Lovd as [Likely_benign].
BS2
High AC in GnomAdExome4 at 65 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
FBN1NM_000138.5 linkuse as main transcriptc.1837+4C>T splice_region_variant, intron_variant ENST00000316623.10 NP_000129.3 P35555
FBN1NM_001406716.1 linkuse as main transcriptc.1837+4C>T splice_region_variant, intron_variant NP_001393645.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
FBN1ENST00000316623.10 linkuse as main transcriptc.1837+4C>T splice_region_variant, intron_variant 1 NM_000138.5 ENSP00000325527.5 P35555

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152164
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
GnomAD3 exomes
AF:
0.0000477
AC:
12
AN:
251320
Hom.:
0
AF XY:
0.0000663
AC XY:
9
AN XY:
135832
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 SAS exome
AF:
0.0000654
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000792
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000445
AC:
65
AN:
1461414
Hom.:
0
Cov.:
32
AF XY:
0.0000481
AC XY:
35
AN XY:
727028
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000464
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000486
Gnomad4 OTH exome
AF:
0.0000828
GnomAD4 genome
AF:
0.0000263
AC:
4
AN:
152164
Hom.:
0
Cov.:
32
AF XY:
0.0000404
AC XY:
3
AN XY:
74324
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000441
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.000115
Hom.:
0
Bravo
AF:
0.0000416
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

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

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1Benign:1
Uncertain significance, criteria provided, single submitterclinical testingAmbry GeneticsJun 21, 2022The c.1837+4C>T intronic variant results from a C to T substitution 4 nucleotides after coding exon 14 in the FBN1 gene. This alteration has been reported in a Marfan syndrome cohort (Madar L et al. J Biotechnol, 2019 Aug;301:105-111). This nucleotide position is poorly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will not have any significant effect on splicing. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Likely benign, criteria provided, single submitterclinical testingColor Diagnostics, LLC DBA Color HealthDec 13, 2018- -
Marfan syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJul 02, 2022This sequence change falls in intron 15 of the FBN1 gene. It does not directly change the encoded amino acid sequence of the FBN1 protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs199950267, gnomAD 0.006%). This variant has been observed in individual(s) with clinical features of Marfan syndrome (PMID: 17657824, 31163209). ClinVar contains an entry for this variant (Variation ID: 406295). 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 provided Benign:1
Benign, criteria provided, single submitterclinical testingGeneDxMar 03, 2015This variant is associated with the following publications: (PMID: 31163209) -
FBN1-related disorder Benign:1
Likely benign, no assertion criteria providedclinical testingPreventionGenetics, part of Exact SciencesMar 06, 2024This 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). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.75
CADD
Benign
11
DANN
Benign
0.64

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.00013
dbscSNV1_RF
Benign
0.074
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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs199950267; hg19: chr15-48800775; API