chr9-132905618-G-GT
Variant summary
Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000368.5(TSC1):c.1959dupA(p.Gln654ThrfsTer34) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,876 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.
Frequency
Consequence
NM_000368.5 frameshift
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: Pathogenic. The variant received 18 ACMG points.
Variant Effect in Transcripts
ACMG analysis was done for transcript: NM_000368.5. You can select a different transcript below to see updated ACMG assignments.
RefSeq Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| TSC1 | NM_000368.5 | MANE Select | c.1959dupA | p.Gln654ThrfsTer34 | frameshift | Exon 15 of 23 | NP_000359.1 | ||
| TSC1 | NM_001406592.1 | c.1959dupA | p.Gln654ThrfsTer34 | frameshift | Exon 15 of 23 | NP_001393521.1 | |||
| TSC1 | NM_001406593.1 | c.1959dupA | p.Gln654ThrfsTer34 | frameshift | Exon 15 of 23 | NP_001393522.1 |
Ensembl Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| TSC1 | ENST00000298552.9 | TSL:1 MANE Select | c.1959dupA | p.Gln654ThrfsTer34 | frameshift | Exon 15 of 23 | ENSP00000298552.3 | ||
| TSC1 | ENST00000490179.4 | TSL:3 | c.1959dupA | p.Gln654ThrfsTer34 | frameshift | Exon 16 of 24 | ENSP00000495533.2 | ||
| TSC1 | ENST00000643875.1 | c.1959dupA | p.Gln654ThrfsTer34 | frameshift | Exon 15 of 23 | ENSP00000495158.1 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251330 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 6.84e-7 AC: 1AN: 1461876Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0AN XY: 727236 show subpopulations
Age Distribution
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Tuberous sclerosis 1 Pathogenic:7
For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in TSC1 are known to be pathogenic (PMID: 10227394, 17304050). This variant has been observed in individuals affected with tuberous sclerosis complex (PMID: 16981987) and in the Leiden Open-source Variation Database (PMID: 21520333). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Gln654Thrfs*34) in the TSC1 gene. It is expected to result in an absent or disrupted protein product.
Absent from controls (or at extremely low frequency if recessive) in Genome Aggregation Database, Exome Sequencing Project, 1000 Genomes Project, or Exome Aggregation Consortium.;Null variant in a gene where loss of function (LOF) is a known mechanism of disease.;The prevalence of the variant in affected individuals is significantly increased compared to the prevalence in controls.;Patient's phenotype or family history is highly specific for a disease with a single genetic etiology.
The TSC1 variant c.1959dup, p.Gln654Thrfs*34 creates a shift in the reading frame at position 654, introducing a premature stop codon 34 amino acids downstream. This is predicted to result in a loss or disruption of normal protein function through non-sense mediated decay (NMD) or protein truncation. This variant is observed at an extremely low frequency in the gnomAD v4.1.0 dataset (total allele frequency: <0.001%) and has previously been reported in the literature as disease-causing in patients with autosomal dominant Tuberous sclerosis-1 (PMID: 17304050, 16981987, 10227394). It is classified as pathogenic (class 1) according to the recommendations of ACMG/AMP/ClinGen SVI guidelines.
ACMG Criteria: PVS1, PM1, PM2, PP5; Variant was found in heterozygous state.
Hereditary cancer-predisposing syndrome Pathogenic:1
The c.1959dupA pathogenic mutation, located in coding exon 13 of the TSC1 gene, results from a duplication of A at nucleotide position 1959, causing a translational frameshift with a predicted alternate stop codon (p.Q654Tfs*34). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation.
Tuberous sclerosis syndrome Other:1
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at