rs137854052

Variant names:

• chr16-2058765-G-GC
• rs137854052
• NM_000548.5:c.871dupC

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000548.5(TSC2):​c.871dupC​(p.Leu291ProfsTer47) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. L291L) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: TSC2 NM_000548.5 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1 O:1
• Conservation: PhyloP100: 2.76
• Publications: 2 publications found

Genes affected

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]

TSC2 Gene-Disease associations (from GenCC):

• tuberous sclerosis

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• tuberous sclerosis 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, Ambry Genetics
• lymphangioleiomyomatosis

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• tuberous sclerosis complex

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 16-2058765-G-GC is Pathogenic according to our data. Variant chr16-2058765-G-GC is described in ClinVar as Pathogenic. ClinVar VariationId is 49932.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.871dupC	p.Leu291ProfsTer47	frameshift_variant	Exon 10 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.871dupC	p.Leu291ProfsTer47	frameshift_variant	Exon 10 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Tuberous sclerosis syndrome Pathogenic:1 Other:1

Apr 30, 2018

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Leu291fs variant in TSC2 has been reported in 1 individual with tuberous s clerosis complex (TSC; Franz 2001, Dabora 2001), and was absent from large popul ation studies. This variant is predicted to cause a frameshift, which alters the protein?s amino acid sequence beginning at position 291 and leads to a prematur e termination codon 47 amino acids downstream. This alteration is then predicted to lead to a truncated or absent protein. Heterozygous loss of function of the TSC2 gene is an established disease mechanism in individuals with TSC. In summar y, this variant meets criteria to be classified as pathogenic for TSC in an auto somal dominant manner based upon the predicted impact on the protein and absence in the general population. ACMG/AMP Criteria applied: PVS1, PM2, PS4_Supporting . -

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Tuberous sclerosis database (TSC2)

Significance: not provided

Review Status: no classification provided

Collection Method: curation

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		2.8
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs137854052; hg19: chr16-2108766;