chr9-132896380-A-C

Variant names:

• chr9-132896380-A-C
• rs762641110
• NM_000368.5:c.3350T>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_000368.5(TSC1):​c.3350T>G​(p.Leu1117Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,894 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L1117P) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: TSC1 NM_000368.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.88
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• tuberous sclerosis

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• tuberous sclerosis 1

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

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

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC1	NM_000368.5	c.3350T>G	p.Leu1117Arg	missense_variant	Exon 23 of 23	ENST00000298552.9	NP_000359.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC1	ENST00000298552.9	c.3350T>G	p.Leu1117Arg	missense_variant	Exon 23 of 23	1	NM_000368.5	ENSP00000298552.3
TSC1	ENST00000490179.4	c.3350T>G	p.Leu1117Arg	missense_variant	Exon 24 of 24	3		ENSP00000495533.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461894 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727248

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Tuberous sclerosis 1 Uncertain:1

Oct 30, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 1117 of the TSC1 protein (p.Leu1117Arg). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TSC1-related conditions. Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on TSC1 protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Pathogenic	0.17	D
BayesDel_noAF	Uncertain	0.010
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.42	T;.;T;.;.;T;.;T;.;.;.
Eigen	Uncertain	0.41
Eigen_PC	Uncertain	0.35
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.88	.;D;D;D;D;.;.;.;D;D;.
M_CAP	Pathogenic	0.32	D
MetaRNN	Uncertain	0.53	D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.63	D
MutationAssessor	Uncertain	2.4	M;.;M;.;.;M;.;M;.;.;.
PhyloP100		4.9
PrimateAI	Uncertain	0.52	T
PROVEAN	Benign	-1.7	N;N;N;.;.;.;.;.;.;.;.
REVEL	Uncertain	0.64
Sift	Uncertain	0.0010	D;D;D;.;.;.;.;.;.;.;.
Sift4G	Uncertain	0.0020	D;D;D;.;.;.;.;.;.;.;.
Polyphen		0.95	P;.;P;.;.;P;.;P;.;.;.
Vest4		0.41
MutPred		0.36		Loss of stability (P = 0.0081);.;Loss of stability (P = 0.0081);.;.;Loss of stability (P = 0.0081);.;Loss of stability (P = 0.0081);.;.;.;
MVP		0.47
MPC		1.2
ClinPred		0.92	D
GERP RS		4.5
Varity_R		0.51
gMVP		0.77
Mutation Taster		=70/30	polymorphism

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: rs762641110; hg19: chr9-135771767;