Our verdict is Likely benign. Variant got -2 ACMG points: 3P and 5B. PM5PP3BP6BS2
The NM_000548.5(TSC2):āc.1362G>Cā(p.Arg454Ser) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000222 in 1,398,054 control chromosomes in the GnomAD database, with no homozygous occurrence. 2/3 splice prediction tools predicting alterations to normal splicing. 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. R454K) has been classified 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]
Verdict is Likely_benign. Variant got -2 ACMG points.
PM5
Other missense variant is known to change same aminoacid residue: Variant chr16-2062600-G-A is described in Lovd as [Pathogenic].
PP3
Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. Scorers claiming Uncertain: max_spliceai. No scorers claiming Benign.
BP6
Variant 16-2062972-G-C is Benign according to our data. Variant chr16-2062972-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 406041.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=4, Uncertain_significance=1}.
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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Jan 13, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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Tuberous sclerosis syndrome Uncertain:1
Nov 02, 2023
All of Us Research Program, National Institutes of Health
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This missense variant replaces arginine with serine at codon 454 of the TSC2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). Splice site prediction tools suggest that this variant may impact RNA splicing. To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with TSC2-related disorders in the literature. This variant has been identified in 2/155160 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. -
not provided Benign:1
Sep 08, 2020
GeneDx
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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Hereditary cancer-predisposing syndrome Benign:1
May 21, 2021
Ambry Genetics
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -