9-132896437-T-C

Variant names:

• chr9-132896437-T-C
• rs1554812687
• NM_000368.5:c.3293A>G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4 BP6

The NM_000368.5(TSC1):​c.3293A>G​(p.Asn1098Ser) 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. In-silico tool predicts 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. N1098H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: TSC1 NM_000368.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1
• Conservation: PhyloP100: 5.41
• 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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.37821364).
• BP6: Variant 9-132896437-T-C is Benign according to our data. Variant chr9-132896437-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 466129.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC1	NM_000368.5	c.3293A>G	p.Asn1098Ser	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.3293A>G	p.Asn1098Ser	missense_variant	Exon 23 of 23	1	NM_000368.5	ENSP00000298552.3
TSC1	ENST00000490179.4	c.3293A>G	p.Asn1098Ser	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

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Tuberous sclerosis 1 Uncertain:1 Benign:1

Nov 07, 2021

Genome-Nilou Lab

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Feb 02, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

not provided Uncertain:1

Dec 09, 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

Hereditary cancer-predisposing syndrome Uncertain:1

Apr 21, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.N1098S variant (also known as c.3293A>G), located in coding exon 21 of the TSC1 gene, results from an A to G substitution at nucleotide position 3293. The asparagine at codon 1098 is replaced by serine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. 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	0.33
BayesDel_addAF	Benign	0.00086	T
BayesDel_noAF	Benign	-0.24
CADD	Uncertain	23
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.43	T;.;T;.;.;T;.;T;.;.;.
Eigen	Uncertain	0.68
Eigen_PC	Uncertain	0.66
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Benign	0.0	.;D;D;D;D;.;.;.;D;D;.
M_CAP	Uncertain	0.13	D
MetaRNN	Benign	0.38	T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.47	D
MutationAssessor	Uncertain	2.4	M;.;M;.;.;M;.;M;.;.;.
PhyloP100		5.4
PrimateAI	Uncertain	0.67	T
PROVEAN	Benign	-1.3	N;N;N;.;.;.;.;.;.;.;.
REVEL	Uncertain	0.37
Sift	Pathogenic	0.0	D;D;D;.;.;.;.;.;.;.;.
Sift4G	Benign	0.14	T;T;T;.;.;.;.;.;.;.;.
Vest4		0.41
ClinPred		0.91	D
GERP RS		5.6
Varity_R		0.36
gMVP		0.41
Mutation Taster		=84/16	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: rs1554812687; hg19: chr9-135771824;