9-132906734-CTTCT-C

Position:

• chr9-132906734-CTTCT-C

Variant summary

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

The NM_000368.5(TSC1):​c.1431_1434delAGAA​(p.Glu478fs) 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: 32)
• Consequence: TSC1 NM_000368.5 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:8 O:1
• Conservation: PhyloP100: 4.78

Genes affected

TSC1 (HGNC:12362): (TSC complex subunit 1) This gene is a tumor suppressor gene that encodes the growth inhibitory protein hamartin. The encoded protein interacts with and stabilizes the GTPase activating protein tuberin. This hamartin-tuberin complex negatively regulates mammalian target of rapamycin complex 1 (mTORC1) signaling which is a major regulator of anabolic cell growth. This protein also functions as a co-chaperone for Hsp90 that inhibits its ATPase activity. This protein functions as a facilitator of Hsp90-mediated folding of kinase and non-kinase clients, including TSC2 and thereby preventing their ubiquitination and proteasomal degradation. Mutations in this gene have been associated with tuberous sclerosis and lymphangioleiomyomatosis. [provided by RefSeq, May 2022]

TSC1 (HGNC:):

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 9-132906734-CTTCT-C is Pathogenic according to our data. Variant chr9-132906734-CTTCT-C is described in ClinVar as [Pathogenic]. Clinvar id is 48779.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr9-132906734-CTTCT-C is described in Lovd as [Pathogenic]. Variant chr9-132906734-CTTCT-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TSC1	NM_000368.5	c.1431_1434delAGAA	p.Glu478fs	frameshift_variant	14/23	ENST00000298552.9	NP_000359.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TSC1	ENST00000298552.9	c.1431_1434delAGAA	p.Glu478fs	frameshift_variant	14/23	1	NM_000368.5	ENSP00000298552.3
TSC1	ENST00000490179.4	c.1431_1434delAGAA	p.Glu478fs	frameshift_variant	15/24	3		ENSP00000495533.2

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:8 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Tuberous sclerosis 1 Pathogenic:4

Pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Athena Diagnostics	May 30, 2014	- -
Pathogenic, criteria provided, single submitter	clinical testing	MGZ Medical Genetics Center	Jun 28, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Sep 01, 2023	This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with TSC1-related conditions (PMID: 21520333). ClinVar contains an entry for this variant (Variation ID: 48779). For these reasons, this variant has been classified as Pathogenic. This sequence change creates a premature translational stop signal (p.Glu478Lysfs*53) in the TSC1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in TSC1 are known to be pathogenic (PMID: 10227394, 17304050). -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jul 03, 2024	Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 27535533, 17304050, 35870981) -
Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jun 01, 2019	- -

Lymphangiomyomatosis;C1846385:Isolated focal cortical dysplasia type II;C1854465:Tuberous sclerosis 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Mar 08, 2024

- -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 25, 2024

The c.1431_1434delAGAA pathogenic mutation, located in coding exon 12 of the TSC1 gene, results from a deletion of 4 nucleotides at nucleotide positions 1431 to 1434, causing a translational frameshift with a predicted alternate stop codon (p.E478Kfs*53). This variant has been reported in multiple individuals with features consistent with tuberous sclerosis complex (TSC) (Au KS et al. Genet Med, 2007 Feb;9:88-100; Luo C et al. Front Med (Lausanne), 2021 Nov;8:744050). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Tuberous sclerosis syndrome Other:1

not provided, no classification provided

curation

Tuberous sclerosis database (TSC1)

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- -

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: rs118203527; hg19: chr9-135782121;