16-2062962-C-A
Variant summary
Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3PP5
The NM_000548.5(TSC2):c.1362-10C>A variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000716 in 1,397,076 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000548.5 intron
Scores
Clinical Significance
Conservation
Publications
- tuberous sclerosisInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- tuberous sclerosis 2Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, Ambry Genetics
- lymphangioleiomyomatosisInheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
- tuberous sclerosis complexInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Uncertain_significance. The variant received 4 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 33
GnomAD4 exome AF: 7.16e-7 AC: 1AN: 1397076Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0AN XY: 689098 show subpopulations
GnomAD4 genome Cov.: 33
ClinVar
Submissions by phenotype
not provided Pathogenic:3
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports a deleterious effect on splicing; This variant is associated with the following publications: (PMID: 10735580, 26540169, 17304050) -
This variant has been identified in multiple unrelated individuals with clinical features associated with this gene. Some individuals were reported to have a variable and/or mild presentation (PMID: 10735580, 17304050, 26540169, internal patient(s), and personal communication related to ClinVar ID: 50185, Accession: SCV000644236.7). This variant has not been reported in large, multi-ethnic general populations. (http://gnomad.broadinstitute.org) Computational tools yielded predictions that this variant may interfere with normal RNA splicing. RT-PCR analysis was unable to confirm an effect on RNA splicing, however it is uncertain whether the detection method used would identify a small, in-frame length change of this exon (PMID: 26540169). -
The TSC2 c.1362-10C>A variant (rs45446697) has been observed in several individuals and families with TSC2-related disease (Choy 1999, Tyburczy 2015, ARUP internal data, personal communication). This variant is also reported in ClinVar (Variation ID: 50185). It is absent from the Genome Aggregation Database (v2.1.1), indicating it is not a common polymorphism. This is an intronic variant and computational analyses (Alamut Visual Plus v.1.5.1) predict that this variant may impact splicing by weakening the nearby canonical acceptor splice site. Based on available information, this variant is considered to be likely pathogenic. References: Choy YS et al. Superiority of denaturing high performance liquid chromatography over single-stranded conformation and conformation-sensitive gel electrophoresis for mutation detection in TSC2. Ann Hum Genet. 1999 Sep;63(Pt 5):383-91. PMID: 10735580. Tyburczy ME et al. Mosaic and Intronic Mutations in TSC1/TSC2 Explain the Majority of TSC Patients with No Mutation Identified by Conventional Testing. PLoS Genet. 2015 Nov 5;11(11):e1005637. PMID: 26540169. -
Tuberous sclerosis 2 Pathogenic:1Uncertain:1Benign:1
ACMG codes: PM2, PP3 -
This sequence change falls in intron 13 of the TSC2 gene. It does not directly change the encoded amino acid sequence of the TSC2 protein. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individuals with tuberous sclerosis complex (PMID: 26540169; internal data). ClinVar contains an entry for this variant (Variation ID: 50185). Studies have shown that this variant is associated with inconclusive levels of altered splicing (internal data). For these reasons, this variant has been classified as Pathogenic. -
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Isolated focal cortical dysplasia type II Pathogenic:1
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Hereditary cancer-predisposing syndrome Pathogenic:1
The c.1362-10C>A intronic pathogenic mutation results from a C to A substitution 10 nucleotides upstream from coding exon 13 in the TSC2 gene. This alteration has been observed in many individuals with a personal and/or family history that is consistent with TSC2-related disease (Ambry internal data; Personal communication; Tyburczy ME et al. PLoS Genet, 2015 Nov;11:e1005637; Choy YS et al. Ann Hum Genet, 1999 Sep;63:383-91). In silico splice site analysis predicts that this alteration will weaken the native splice acceptor site. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
TSC2-related disorder Uncertain:1
The TSC2 c.1362-10C>A variant is predicted to interfere with splicing. The c.1362-10 C>A intronic variant in the TSC2 gene has been reported in individuals affected with tuberous sclerosis, and has been reported to segregate with affected status within a family; however, minimal details were provided (Tyburczy et al. 2015. PubMed ID: 26540169; Choy et al. 1999. PubMed ID: 10735580; Au et al. 2007. PubMed ID: 17304050; https://databases.lovd.nl/shared/variants/TSC2). This variant is predicted to abolish the canonical splice acceptor site based on available splicing prediction programs (Alamut Visual Plus v1.6.1). However, the use of computer prediction programs is not equivalent to functional evidence. In ClinVar this variant has conflicting classifications including pathogenic, likely pathogenic, uncertain significance, and benign (https://preview.ncbi.nlm.nih.gov/clinvar/variation/50185/). Although we suspect that this variant may be pathogenic, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Tuberous sclerosis syndrome Other:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at