chr9-132911038-G-T

Position:

• chr9-132911038-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_000368.5(TSC1):​c.1105C>A​(p.Leu369Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000131 in 152,210 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. L369L) has been classified as Benign.

• Frequency: Genomes: 𝑓 0.000013 (0 hom., cov: 31)
• Consequence: TSC1 NM_000368.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: -0.328

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 Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), TSC1. . Gene score misZ 2.3217 (greater than the threshold 3.09). Trascript score misZ 3.6986 (greater than threshold 3.09). GenCC has associacion of gene with lung lymphangioleiomyomatosis, tuberous sclerosis 1, tuberous sclerosis, tuberous sclerosis complex, lymphangioleiomyomatosis.
• BP4: Computational evidence support a benign effect (MetaRNN=0.14086163).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TSC1	NM_000368.5	c.1105C>A	p.Leu369Met	missense_variant	11/23	ENST00000298552.9	NP_000359.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TSC1	ENST00000298552.9	c.1105C>A	p.Leu369Met	missense_variant	11/23	1	NM_000368.5	ENSP00000298552.3
TSC1	ENST00000490179.4	c.1105C>A	p.Leu369Met	missense_variant	12/24	3		ENSP00000495533.2

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152210 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152210 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 74350

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Quest Diagnostics Nichols Institute San Juan Capistrano

Sep 16, 2024

The TSC1 c.1105C>A (p.Leu369Met) variant has not been reported in individuals with TSC1-related conditions in the published literature. The frequency of this variant in the general population, 0.000013 (2/152210 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant. -

Tuberous sclerosis 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 15, 2023

This sequence change replaces leucine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 369 of the TSC1 protein (p.Leu369Met). 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. ClinVar contains an entry for this variant (Variation ID: 237695). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt TSC1 protein function with a negative predictive value of 95%. 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. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 06, 2022

The p.L369M variant (also known as c.1105C>A), located in coding exon 9 of the TSC1 gene, results from a C to A substitution at nucleotide position 1105. The leucine at codon 369 is replaced by methionine, an amino acid with highly similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.088
BayesDel_addAF	Benign	-0.055	T
BayesDel_noAF	Benign	-0.32
CADD	Benign	7.3
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.45	T;.;T;.;T;.;T;.;.;.;.;.;.;.;.
Eigen	Benign	-0.55
Eigen_PC	Benign	-0.73
FATHMM_MKL	Benign	0.16	N
LIST_S2	Benign	0.66	.;T;T;T;.;.;.;T;T;.;.;.;T;T;T
M_CAP	Benign	0.061	D
MetaRNN	Benign	0.14	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.11	T
MutationAssessor	Benign	1.9	L;.;L;.;L;.;L;.;.;.;.;.;.;.;.
PrimateAI	Benign	0.27	T
PROVEAN	Benign	-0.52	N;N;N;.;.;.;.;.;.;.;.;.;.;.;.
REVEL	Uncertain	0.34
Sift	Uncertain	0.026	D;D;D;.;.;.;.;.;.;.;.;.;.;.;.
Sift4G	Uncertain	0.032	D;D;D;.;.;.;.;.;.;.;.;.;.;.;.
Polyphen		0.48	P;.;P;.;P;.;P;.;.;.;D;D;D;.;.
Vest4		0.23
MutPred		0.47		Loss of catalytic residue at L369 (P = 0.0731);.;Loss of catalytic residue at L369 (P = 0.0731);Loss of catalytic residue at L369 (P = 0.0731);Loss of catalytic residue at L369 (P = 0.0731);Loss of catalytic residue at L369 (P = 0.0731);Loss of catalytic residue at L369 (P = 0.0731);Loss of catalytic residue at L369 (P = 0.0731);Loss of catalytic residue at L369 (P = 0.0731);.;Loss of catalytic residue at L369 (P = 0.0731);Loss of catalytic residue at L369 (P = 0.0731);Loss of catalytic residue at L369 (P = 0.0731);Loss of catalytic residue at L369 (P = 0.0731);.;
MVP		0.45
MPC		1.1
ClinPred		0.40	T
GERP RS		-3.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.072
gMVP		0.23

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs118203496; hg19: chr9-135786425;