5-128339011-C-T
Variant summary
Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP6BS1BS2
The NM_001999.4(FBN2):c.3394G>A(p.Val1132Ile) variant causes a missense change. The variant allele was found at a frequency of 0.000288 in 1,613,794 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_001999.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Benign. Variant got -9 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000197 AC: 30AN: 152170Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.000163 AC: 41AN: 251394Hom.: 0 AF XY: 0.000132 AC XY: 18AN XY: 135872
GnomAD4 exome AF: 0.000298 AC: 435AN: 1461624Hom.: 0 Cov.: 31 AF XY: 0.000271 AC XY: 197AN XY: 727122
GnomAD4 genome AF: 0.000197 AC: 30AN: 152170Hom.: 0 Cov.: 32 AF XY: 0.000188 AC XY: 14AN XY: 74342
ClinVar
Submissions by phenotype
not provided Uncertain:2Benign:1
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The FBN2 c.3394G>A; p.Val1132Ile variant (rs138834515) is reported in the literature in a family affected with adolescent idiopathic scoliosis, although it was not demonstrated to be causative (Jiang 2020). This variant is found in the general population with an overall allele frequency of 0.02% (48/282800 alleles) in the Genome Aggregation Database. The valine at codon 1132 is highly conserved, and computational analyses are uncertain whether this variant is neutral or deleterious (REVEL: 0.431). However, due to limited information, the clinical significance of the p.Val1132Ile variant is uncertain at this time. References: Jiang et al. Exome sequencing analysis identifies frequent oligogenic involvement and FLNB variants in adolescent idiopathic scoliosis. J Med Genet. 2020 Jun;57(6):405-413. PMID: 32381728. -
In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 24205039, 32381728) -
Congenital contractural arachnodactyly Uncertain:1Benign:1
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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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
Familial thoracic aortic aneurysm and aortic dissection Uncertain:1
The p.V1132I variant (also known as c.3394G>A), located in coding exon 26 of the FBN2 gene, results from a G to A substitution at nucleotide position 3394. The valine at codon 1132 is replaced by isoleucine, 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 tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Congenital contractural arachnodactyly;C4015286:Macular degeneration, early-onset Uncertain:1
FBN2 NM_001999.3 exon 26 p.Val1132Ile (c.3394G>A): This variant has not been reported in the literature and is present in 0.03% (7/19946) of East Asian alleles in the Genome Aggregation Database (http://gnomad.broadinstitute.org/variant/5-127674703-C-T). This variant is present in ClinVar (Variation ID:213228). Evolutionary conservation and computational predictive tools suggest that this variant may impact the protein. In summary, data on this variant is insufficient for disease classification. Therefore, the clinical significance of this variant is uncertain. -
not specified Benign:1
Variant summary: FBN2 c.3394G>A (p.Val1132Ile) results in a conservative amino acid change located in the EGF-like domain (IPR000742) of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00016 in 251394 control chromosomes. The observed variant frequency is approximately 3-fold of the estimated maximal expected allele frequency for a pathogenic variant in FBN2 causing Congenital Contractural Arachnodactyly phenotype (4.7e-05). c.3394G>A has been reported in the literature in a family with at least one individual affected with adolescent idiopathic scoliosis, without strong evidence for causality (Jiang_2020). This report does not provide unequivocal conclusions about association of the variant with Congenital Contractural Arachnodactyly. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 32381728). ClinVar contains an entry for this variant (Variation ID: 213228). Based on the evidence outlined above, the variant was classified as likely benign. -
Connective tissue disorder Benign:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at