NM_000368.5:c.878C>T

Variant names:

• chr9-132912317-G-A
• rs756681916
• NM_000368.5:c.878C>T

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_000368.5(TSC1):​c.878C>T​(p.Thr293Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,884 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. 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. T293S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TSC1 NM_000368.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 2.98
• Publications: 2 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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.31844735).

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.878C>T	p.Thr293Ile	missense	Exon 9 of 23	NP_000359.1
	TSC1	NM_001406592.1		c.878C>T	p.Thr293Ile	missense	Exon 9 of 23	NP_001393521.1
	TSC1	NM_001406593.1		c.878C>T	p.Thr293Ile	missense	Exon 9 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.878C>T	p.Thr293Ile	missense	Exon 9 of 23	ENSP00000298552.3
	TSC1	ENST00000490179.4	TSL:3	c.878C>T	p.Thr293Ile	missense	Exon 10 of 24	ENSP00000495533.2
	TSC1	ENST00000403810.6	TSL:1	c.878C>T	p.Thr293Ile	missense	Exon 9 of 10	ENSP00000386093.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251336 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461884 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727238

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

American (AMR) AF: 0.00 AC: 0 AN: 44722

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

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39698

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: 0.00 AC: 0 AN: 1112006

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

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	1	-	Hereditary cancer-predisposing syndrome (1)
-	1	-	Tuberous sclerosis 1 (1)
-	1	-	Tuberous sclerosis syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.035	T
BayesDel_noAF	Benign	-0.12
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.53	D
Eigen	Benign	-0.078
Eigen_PC	Benign	0.044
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.78	T
M_CAP	Benign	0.078	D
MetaRNN	Benign	0.32	T
MetaSVM	Uncertain	0.19	D
MutationAssessor	Uncertain	2.2	M
PhyloP100		3.0
PrimateAI	Benign	0.37	T
PROVEAN	Benign	-1.7	N
REVEL	Benign	0.28
Sift	Uncertain	0.010	D
Sift4G	Uncertain	0.025	D
Polyphen		0.0010	B
Vest4		0.19
MutPred		0.65		Loss of glycosylation at T293 (P = 0.0129)
MVP		0.62
MPC		0.54
ClinPred		0.49	T
GERP RS		4.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.10
gMVP		0.40
Mutation Taster		=85/15	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: rs756681916; hg19: chr9-135787704;