Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PVS1_ModeratePM2
The NM_000548.5(TSC2):c.-30_-30+11del variant causes a splice donor, splice donor 5th base, 5 prime UTR, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).
TSC2 (HGNC:12363): (TSC complex subunit 2) This gene is a tumor suppressor gene that encodes the growth inhibitory protein tuberin. Tuberin interacts with hamartin to form the TSC protein complex which functions in the control of cell growth. This TSC protein complex negatively regulates mammalian target of rapamycin complex 1 (mTORC1) signaling which is a major regulator of anabolic cell growth. Mutations in this gene have been associated with tuberous sclerosis and lymphangioleiomyomatosis. [provided by RefSeq, May 2022]
Verdict is Uncertain_significance. Variant got 4 ACMG points.
PVS1
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PVS1 - null variant (nonsense, frameshift, canonical ±1 or 2 splice sites, initiation codon, single or multiexon deletion) in a gene where LOF is a known mechanism of disease
Splicing variant, NOT destroyed by nmd, known LOF gene, truncates exone, which is 0.0147492625 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
PM2
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PM2 - Absent from controls (or at extremely low frequency if recessive) in Exome Sequencing Project, 1000 Genomes Project, or Exome Aggregation Consortium
Very rare variant in population databases, with high coverage;
Uncertain significance, criteria provided, single submitter
clinical testing
All of Us Research Program, National Institutes of Health
Apr 03, 2023
This variant causes a deletion of 12 nucleotides from the exon 1-intron 1 border within the 5' untranslated regon of the TSC2 gene. This variant is predicted to abolish the intron 1 splice donor site and result in aberrant splicing, however the consequence of this on TSC2 expression is unclear. To our knowledge, RNA studies have not been reported for this variant. This variant has not been reported in individuals affected with tuberous sclerosis in the literature. This variant has been identified in 5/282500 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. -