Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM2PP3_ModeratePP5_Very_Strong
The NM_000548.5(TSC2):c.2742G>A(p.Lys914Lys) variant causes a splice region, synonymous change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely 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 Pathogenic. Variant got 12 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
PP5
Variant 16-2076170-G-A is Pathogenic according to our data. Variant chr16-2076170-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 50103.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2076170-G-A is described in Lovd as [Likely_pathogenic]. Variant chr16-2076170-G-A is described in Lovd as [Pathogenic]. Variant chr16-2076170-G-A is described in Lovd as [Likely_pathogenic].
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This sequence change affects codon 914 of the TSC2 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the TSC2 protein. This variant also falls at the last nucleotide of exon 24, which is part of the consensus splice site for this exon. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with clinical features of tuberous sclerosis complex (PMID: 12015165; internal data). ClinVar contains an entry for this variant (Variation ID: 50103). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
not provided Pathogenic:1
Dec 02, 2022
GeneDx
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
Alters the last nucleotide of the exon and is predicted to destroy the splice donor site and result in aberrant splicing, although in the absence of functional evidence the actual effect of this sequence change is unknown; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 12015165) -