15-48488431-C-T
Variant summary
Our verdict is Uncertain significance. Variant got 5 ACMG points: 9P and 4B. PM1PM5PP2PP3_StrongBS2
The NM_000138.5(FBN1):c.3145G>A(p.Gly1049Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000026 in 1,614,026 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 11/18 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G1049C) has been classified as Likely pathogenic.
Frequency
Consequence
NM_000138.5 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 5 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000329 AC: 5AN: 152146Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000159 AC: 4AN: 251486Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 135914
GnomAD4 exome AF: 0.0000253 AC: 37AN: 1461880Hom.: 0 Cov.: 33 AF XY: 0.0000234 AC XY: 17AN XY: 727244
GnomAD4 genome AF: 0.0000329 AC: 5AN: 152146Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74326
ClinVar
Submissions by phenotype
not provided Uncertain:3
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The p.Gly1049Ser variant in FBN1 has not been previously reported in individuals with Marfan syndrome or familial thoracic aortic aneurysm and was absent from large population studies. This variant has also been reported in ClinVar (Variation ID 457190). Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. One variant involving this codon (p.Gly1049Asp) has been identified in individuals with Marfan syndrome or thoracic aortic aneurysm and dissection. In summary, the clinical significance of this variant is uncertain. ACMG/AMP Criteria applied: PP3. -
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Marfan syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection Pathogenic:1
This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 1049 of the FBN1 protein (p.Gly1049Ser). This variant is present in population databases (rs778181932, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with FBN1-related conditions. ClinVar contains an entry for this variant (Variation ID: 457190). 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 expected to disrupt FBN1 protein function with a positive predictive value of 95%. This variant disrupts the p.Gly1049 amino acid residue in FBN1. Other variant(s) that disrupt this residue have been determined to be pathogenic (Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Marfan syndrome Uncertain:1
This missense variant replaces glycine with serine at codon 1049 of the FBN1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with cardiovascular disorders in the literature. This variant has been identified in 5/282892 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
not specified Uncertain:1
Variant summary: FBN1 c.3145G>A (p.Gly1049Ser) results in a non-conservative amino acid change located in the EGF-like domain (IPR000742) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.6e-05 in 251486 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.3145G>A in individuals affected with Marfan Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Three ClinVar submitters have assessed the variant since 2014: two classified the variant as uncertain significance and one as likely pathogenic. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Familial thoracic aortic aneurysm and aortic dissection Uncertain:1
This missense variant replaces glycine with serine at codon 1049 of the FBN1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with FBN1-related disorders in the literature. This variant has been identified in 5/282892 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Progeroid and marfanoid aspect-lipodystrophy syndrome Uncertain:1
This variant was classified as: Uncertain significance. The available evidence on this variant's pathogenicity is insufficient or conflicting. The following ACMG criteria were applied in classifying this variant: PM1,,PM5,PP3. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at