9-132921857-T-A

Position:

• chr9-132921857-T-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_001406626.1(TSC1):​c.-253A>T variant causes a 5 prime UTR premature start codon gain change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: TSC1 NM_001406626.1 5_prime_UTR_premature_start_codon_gain
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.02

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 2 ACMG points.

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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TSC1	NM_000368.5	c.625A>T	p.Met209Leu	missense_variant	7/23	ENST00000298552.9	NP_000359.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TSC1	ENST00000298552.9	c.625A>T	p.Met209Leu	missense_variant	7/23	1	NM_000368.5	ENSP00000298552.3
TSC1	ENST00000490179.4	c.625A>T	p.Met209Leu	missense_variant	8/24	3		ENSP00000495533.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 06, 2021

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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals affected with TSC1-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces methionine with leucine at codon 209 of the TSC1 protein (p.Met209Leu). The methionine residue is highly conserved and there is a small physicochemical difference between methionine and leucine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.26
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.15
CADD	Uncertain	25
DANN	Benign	0.97
DEOGEN2	Uncertain	0.54	D;.;D;.;D;.;D;.;.;.;.;.;.;.;.;.;.;T;.;.
Eigen	Uncertain	0.48
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.94	.;D;D;D;.;.;.;D;D;.;D;.;.;D;D;D;D;D;D;D
M_CAP	Uncertain	0.12	D
MetaRNN	Uncertain	0.61	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.48	D
MutationAssessor	Uncertain	2.5	M;.;M;.;M;.;M;.;.;.;.;.;.;.;.;.;.;.;.;.
PrimateAI	Uncertain	0.78	T
PROVEAN	Benign	-1.7	N;N;N;.;.;.;.;.;.;.;.;.;.;.;.;.;.;N;.;.
REVEL	Uncertain	0.46
Sift	Benign	0.095	T;T;T;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;.;.
Sift4G	Benign	0.12	T;T;T;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;.;.
Polyphen		0.24	B;.;B;.;B;.;B;.;.;.;.;B;B;B;.;.;.;B;.;.
Vest4		0.58
MutPred		0.54		Gain of helix (P = 0.0022);.;Gain of helix (P = 0.0022);Gain of helix (P = 0.0022);Gain of helix (P = 0.0022);Gain of helix (P = 0.0022);Gain of helix (P = 0.0022);Gain of helix (P = 0.0022);Gain of helix (P = 0.0022);.;.;Gain of helix (P = 0.0022);Gain of helix (P = 0.0022);Gain of helix (P = 0.0022);Gain of helix (P = 0.0022);Gain of helix (P = 0.0022);.;Gain of helix (P = 0.0022);.;Gain of helix (P = 0.0022);
MVP		0.91
MPC		1.3
ClinPred		0.85	D
GERP RS		6.1
Varity_R		0.34
gMVP		0.49

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr9-135797244;