Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2PP3PP5_Moderate
The NM_000548.5(TSC2):c.5160+4A>T variant causes a splice region, 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. 2/3 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 Uncertain_significance. Variant got 5 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. Scorers claiming Uncertain: max_spliceai. No scorers claiming Benign.
PP5
Variant 16-2088143-A-T is Pathogenic according to our data. Variant chr16-2088143-A-T is described in ClinVar as [Pathogenic]. Clinvar id is 3704471.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr16-2088143-A-T is described in Lovd as [Pathogenic]. Variant chr16-2088143-A-T is described in Lovd as [Likely_pathogenic]. Variant chr16-2088143-A-T is described in Lovd as [Pathogenic].
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This sequence change falls in intron 40 of the TSC2 gene. It does not directly change the encoded amino acid sequence of the TSC2 protein. It affects a nucleotide within the consensus splice site. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with tuberous sclerosis complex (PMID: 29314583, 35870981). In at least one individual the variant was observed to be de novo. 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. For these reasons, this variant has been classified as Pathogenic. -