Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000548.5(TSC2):c.2743-1G>C variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).
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]
TSC2 Gene-Disease associations (from GenCC):
tuberous sclerosis
Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
tuberous sclerosis 2
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, Ambry Genetics
lymphangioleiomyomatosis
Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
tuberous sclerosis complex
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
Our verdict: Pathogenic. The variant received 18 ACMG points.
PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 16-2076490-G-C is Pathogenic according to our data. Variant chr16-2076490-G-C is described in ClinVar as Pathogenic. ClinVar VariationId is 49561.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
Canonical splice site variant in a gene for which loss-of-function is a known mechanism of disease; Not observed in large population cohorts (Lek et al., 2016); A different nucleotide change at this same canonical splice site (c.2743-1G>A) has been reported as pathogenic in ClinVar and the published literature in association with TSC (VCV000049560.1; Landrum et al., 2016; Au et al., 2007); This variant is associated with the following publications: (PMID: 12111193, 25525159) -