9-132896452-C-T
Variant summary
Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2
The NM_000368.5(TSC1):c.3278G>A(p.Arg1093Gln) variant causes a missense change. The variant allele was found at a frequency of 0.00000248 in 1,614,172 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R1093L) has been classified as Uncertain significance.
Frequency
Consequence
NM_000368.5 missense
Scores
Clinical Significance
Conservation
Publications
- tuberous sclerosisInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- tuberous sclerosis 1Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, PanelApp Australia, Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae)
- lung lymphangioleiomyomatosisInheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
- tuberous sclerosis complexInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Uncertain_significance. The variant received 2 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| TSC1 | NM_000368.5 | c.3278G>A | p.Arg1093Gln | missense_variant | Exon 23 of 23 | ENST00000298552.9 | NP_000359.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152160Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251470 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 0.00000205 AC: 3AN: 1461894Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1AN XY: 727248 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152278Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74456 show subpopulations
ClinVar
Submissions by phenotype
not provided Uncertain:2
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The de novo R1093Q variant in the TSC1 gene has not been reported previously as a pathogenic variant, nor as a benign variant, to our knowledge. The R1093Q variant was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The R1093Q variant is a semi-conservative amino acid substitution, which may impact secondary protein structure as these residues differ in some properties. This substitution occurs at a position that is conserved across species. In silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. We interpret R1093Q as a variant of uncertain significance. -
Tuberous sclerosis 1 Uncertain:1Benign:1
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Tuberous sclerosis syndrome Uncertain:1
This missense variant replaces arginine with glutamine at codon 1093 of the TSC1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 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 TSC1-related disorders in the literature. This variant has been identified in 1/251470 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. -
Isolated focal cortical dysplasia type II Uncertain:1
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TSC1-related disorder Uncertain:1
The TSC1 c.3278G>A variant is predicted to result in the amino acid substitution p.Arg1093Gln. This variant was reported in an individual with keratoconus without tuberous sclerosis and classified as a variant of uncertain significance (Bykhovskaya et al 2017. PubMed ID: 29261847). This variant is reported in 0.0033% of alleles in individuals of South Asian descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Hereditary cancer-predisposing syndrome Uncertain:1
The p.R1093Q variant (also known as c.3278G>A), located in coding exon 21 of the TSC1 gene, results from a G to A substitution at nucleotide position 3278. The arginine at codon 1093 is replaced by glutamine, 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 deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at