rs397515023

Positions:

• chr16-2084692-GA-G
• chr16-2084692-GA-GAA

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000548.5(TSC2):​c.4473del​(p.Val1492CysfsTer84) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 34)
• Consequence: TSC2 NM_000548.5 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 6.94

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 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 16-2084692-GA-G is Pathogenic according to our data. Variant chr16-2084692-GA-G is described in ClinVar as [Pathogenic]. Clinvar id is 238047.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-2084692-GA-G is described in Lovd as [Pathogenic]. Variant chr16-2084692-GA-G is described in Lovd as [Pathogenic]. Variant chr16-2084692-GA-G is described in Lovd as [Pathogenic]. Variant chr16-2084692-GA-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TSC2	NM_000548.5	c.4473del	p.Val1492CysfsTer84	frameshift_variant	34/42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.4473del	p.Val1492CysfsTer84	frameshift_variant	34/42	5	NM_000548.5	ENSP00000219476

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 34

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Tuberous sclerosis 2 Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 21, 2016	While this particular variant has not been reported in the literature, truncating variants in TSC2 are known to be pathogenic (PMID: 10205261, 17304050). For these reasons, this variant has been classified as Pathogenic. This sequence change deletes 1 nucleotide from exon 34 of the TSC2 mRNA (c.4473delA), causing a frameshift at codon 1492. This creates a premature translational stop signal (p.Val1492Cysfs*84) and is expected to result in an absent or disrupted protein product. -

Lymphangiomyomatosis Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Jan 01, 2016

This variant was classified as: Pathogenic. The following ACMG criteria were applied in classifying this variant: PVS1,PS1,PM2. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Apr 19, 2016

The c.4473delA pathogenic variant in the TSC2 gene has been reported previously in an individual with suspected tuberous sclerosis complex (TSC2 LOVD). The deletion causes a frameshift starting with codon Valine 1492, changes this amino acid to a Cysteine residue and creates a premature Stop codon at position 84 of the new reading frame, denoted p.Val1492CysfsX84. This pathogenic variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. Additionally, it was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. -

Computational scores

Source: dbNSFP v4.3

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

Publications

LitVar

Other links and lift over

dbSNP: rs397515023; hg19: chr16-2134693;