Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000548.5(TSC2):c.2546-2A>G 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]
Verdict is Pathogenic. Variant got 18 ACMG points.
PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 5.5, offset of 28, new splice context is: aggctgccgcacctctacAGgaa. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 16-2075797-A-G is Pathogenic according to our data. Variant chr16-2075797-A-G is described in ClinVar as [Pathogenic]. Clinvar id is 49780.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2075797-A-G is described in Lovd as [Pathogenic]. Variant chr16-2075797-A-G is described in Lovd as [Pathogenic].
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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Dec 22, 2020
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
For these reasons, this variant has been classified as Pathogenic. This sequence change affects an acceptor splice site in intron 22 of the TSC2 gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. This variant is not present in population databases (ExAC no frequency). Dirurption of this splice site has been observed in individual(s) with clinical features of tuberous sclerosis complex (PMID: 16981987, 29432982). ClinVar contains an entry for this variant (Variation ID: 49780). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. Donor and acceptor splice site variants typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in TSC2 are known to be pathogenic (PMID: 10205261, 17304050). -
not provided Pathogenic:1
Oct 27, 2014
Eurofins Ntd Llc (ga)
Significance: Pathogenic
Review Status: criteria provided, single submitter