Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PVS1_StrongPM2PP5_Very_Strong
The NM_000548.5(TSC2):c.5266delG(p.Glu1756ArgfsTer70) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. E1756E) has been classified as Likely benign.
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 14 ACMG points.
PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 12 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 16-2088451-CG-C is Pathogenic according to our data. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2088451-CG-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 238080.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
This sequence change deletes 1 nucleotide from exon 42 of the TSC2 mRNA (c.5266delG), causing a frameshift at codon 1756. This creates a premature translational stop signal in the last exon of the TSC2 mRNA (p.Glu1756Argfs*70). While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 52 amino acids of the TSC2 protein. This variant has not been reported in the literature in individuals with TSC2-related conditions. ClinVar contains an entry for this variant (Variation ID: 238080). Multiple frameshift variants, including c.5340_5371del (p.1784Alafs*?) and c.5405_5408dup (p.Phe1803Leufs*42) located downstream of this variant, have been reported as de novo disease-causing variants in individuals affected with tuberous sclerosis complex (PMID: 10205261, 9328481, 24789117). This suggests that frameshift variants affecting the very C-terminus of TSC2 impact protein function and cause disease. Functional studies using animal models have shown that the C-terminus of the TSC2 protein is involved in tumor suppression (PMID: 8799170, 17379185). For these reasons, this variant has been classified as Pathogenic. This variant is not present in population databases (ExAC no frequency). -
not providedPathogenic:1
Mar 04, 2022
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing
The TSC2 c.5266delG; p.Glu1756ArgfsTer70 variant (rs878854118), to our knowledge, is not reported in the medical literaturE. However, frameshift variants that occur downstream of this variant have been described in affected individuals and are considered pathogenic (Ding 2020, Lindy 2018, Liu 2018). The variant is listed in the ClinVar database (Variation ID: 238080) and is absent from the Genome Aggregation Database, indicating it is not a common polymorphism. This variant results in a premature termination codon in the last exon of the TSC2 gene. While this may not lead to nonsense-mediated decay, it is expected to create a truncated TSC2 protein. This region of TSC2 encodes the GAP domain, critical for tumor suppression (Jin 1996, Momose 2007). Based on available information, this variant is classified as likely pathogenic. References: Ding Y et al. Genotype and Phenotype Analysis of Chinese Children With Tuberous Sclerosis Complex: A Pediatric Cohort Study. Front Genet. 2020 Mar 10;11:204. PMID: 32211034. Jin F et al. Suppression of tumorigenicity by the wild-type tuberous sclerosis 2 (Tsc2) gene and its C-terminal region. Proc Natl Acad Sci U S A. 1996 Aug 20;93(17):9154-9. PMID: 8799170. Lindy AS et al. Diagnostic outcomes for genetic testing of 70 genes in 8565 patients with epilepsy and neurodevelopmental disorders. Epilepsia. 2018 May;59(5):1062-1071. PMID: 29655203. Liu J et al. Novel and de novo mutations in pediatric refractory epilepsy. Mol Brain. 2018 Sep 5;11(1):48. PMID: 30185235 Jin F et al. Suppression of tumorigenicity by the wild-type tuberous sclerosis 2 (Tsc2) gene and its C- Momose S et al. N-terminal hamartin-binding and C-terminal GAP domain of tuberin can separate in vivo. Biochem Biophys Res Commun. 2007 May 11;356(3):693-8. PMID: 17379185. -