Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000548.5(TSC2):c.2356-1G>A 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, No cryptic splice site detected. Exon removal results in frameshift change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 16-2074199-G-A is Pathogenic according to our data. Variant chr16-2074199-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 49204.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2074199-G-A is described in Lovd as [Pathogenic]. Variant chr16-2074199-G-A is described in Lovd as [Pathogenic].
Division of Genomic Medicine, Department of Advanced Medicine, Medical Research Institute, Kanazawa Medical University
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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Nov 07, 2021
Genome-Nilou Lab
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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not provided Pathogenic:1
Mar 30, 2021
GeneDx
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
Canonical splice site variant predicted to result in a null allele in a gene for which loss-of-function is a known mechanism of disease; Not observed in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 23389244, 10942116, 25525159) -
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The c.2356-1G>A intronic pathogenic mutation results from a G to A substitution one nucleotide upstream from coding exon 21 of the TSC2 gene. This mutation was identified in two individuals meeting diagnostic criteria for tuberous sclerosis (Jones AC et al. Hum. Genet., 2000 Jun;106:663-8; Niida Y et al. J. Hum. Genet., 2013 Apr;58:216-25). In addition to the clinical data presented in the literature, alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. As such, this alteration is classified as a disease-causing mutation. -