chr9-132896530-A-G

Variant names:

• chr9-132896530-A-G
• rs1167362899
• NM_000368.5:c.3200T>C

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP6

The NM_000368.5(TSC1):​c.3200T>C​(p.Met1067Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M1067R) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: TSC1 NM_000368.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:1
• Conservation: PhyloP100: 0.0960
• 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: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.072118014).
• BP6: Variant 9-132896530-A-G is Benign according to our data. Variant chr9-132896530-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 856614.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000368.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TSC1	NM_000368.5	MANE Select	c.3200T>C	p.Met1067Thr	missense	Exon 23 of 23	NP_000359.1
	TSC1	NM_001406592.1		c.3200T>C	p.Met1067Thr	missense	Exon 23 of 23	NP_001393521.1
	TSC1	NM_001406593.1		c.3200T>C	p.Met1067Thr	missense	Exon 23 of 23	NP_001393522.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TSC1	ENST00000298552.9	TSL:1 MANE Select	c.3200T>C	p.Met1067Thr	missense	Exon 23 of 23	ENSP00000298552.3
	TSC1	ENST00000490179.4	TSL:3	c.3200T>C	p.Met1067Thr	missense	Exon 24 of 24	ENSP00000495533.2
	TSC1	ENST00000643875.1		c.3200T>C	p.Met1067Thr	missense	Exon 23 of 23	ENSP00000495158.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1

Feb 22, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge

Tuberous sclerosis 1 Uncertain:1

May 04, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 1067 of the TSC1 protein (p.Met1067Thr). 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: 856614). 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 Benign:1

Feb 27, 2024

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.057
BayesDel_addAF	Benign	-0.16	T
BayesDel_noAF	Benign	-0.46
CADD	Benign	0.068
DANN	Benign	0.21
DEOGEN2	Benign	0.30	T
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.4
FATHMM_MKL	Benign	0.16	N
LIST_S2	Benign	0.42	T
M_CAP	Benign	0.076	D
MetaRNN	Benign	0.072	T
MetaSVM	Benign	-0.58	T
MutationAssessor	Benign	0.41	N
PhyloP100		0.096
PrimateAI	Benign	0.30	T
PROVEAN	Benign	0.080	N
REVEL	Benign	0.24
Sift	Benign	0.32	T
Sift4G	Benign	0.47	T
Polyphen		0.0	B
Vest4		0.044
MutPred		0.17		Gain of relative solvent accessibility (P = 0.0215)
MVP		0.27
MPC		0.58
ClinPred		0.043	T
GERP RS		-1.3
Varity_R		0.038
gMVP		0.11
Mutation Taster		=98/2	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: rs1167362899; hg19: chr9-135771917;