rs748692173

Variant names:

• chr16-2055424-G-A
• NM_000548.5:c.504G>A

Your query was ambiguous. Multiple possible variants found:

• chr16-2055424-G-A
• chr16-2055424-G-T

Variant summary

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

The NM_000548.5(TSC2):​c.504G>A​(p.Met168Ile) variant causes a missense 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 (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely benign in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M168V) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 31)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 9.42

Genes affected

TSC2 (HGNC:12363): (TSC complex subunit 2) This gene is a tumor suppressor gene that encodes the growth inhibitory protein tuberin. Tuberin interacts with hamartin to form the TSC protein complex which functions in the control of cell growth. This TSC protein complex negatively regulates mammalian target of rapamycin complex 1 (mTORC1) signaling which is a major regulator of anabolic cell growth. Mutations in this gene have been associated with tuberous sclerosis and lymphangioleiomyomatosis. [provided by RefSeq, May 2022]

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 rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.504G>A	p.Met168Ile	missense_variant	Exon 6 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.504G>A	p.Met168Ile	missense_variant	Exon 6 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Tuberous sclerosis 2 Uncertain:1

Dec 09, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is not present in population databases (gnomAD no frequency). 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. 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 TSC2 protein function. This variant has not been reported in the literature in individuals affected with TSC2-related conditions. This sequence change replaces methionine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 168 of the TSC2 protein (p.Met168Ile). -

Hereditary cancer-predisposing syndrome Uncertain:1

Oct 29, 2020

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.M168I variant (also known as c.504G>A), located in coding exon 5 of the TSC2 gene, results from a G to A substitution at nucleotide position 504. The methionine at codon 168 is replaced by isoleucine, 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 deleterious 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	Pathogenic	0.76
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.19
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Benign	0.38	T;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Uncertain	0.44
Eigen_PC	Uncertain	0.50
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.88	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.37	D
MetaRNN	Uncertain	0.57	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	-0.23	T
MutationAssessor	Benign	1.6	L;.;.;.;L;L;.;.;.;L;.;L;.;.;.
PrimateAI	Uncertain	0.59	T
PROVEAN	Benign	-1.0	N;.;.;N;.;N;.;.;N;N;.;.;.;.;N
REVEL	Uncertain	0.56
Sift	Benign	0.37	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Sift4G	Uncertain	0.017	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Polyphen		0.86	P;.;.;.;.;P;.;.;D;B;.;.;.;.;.
Vest4		0.88
MutPred		0.44		Loss of catalytic residue at V164 (P = 0.0151);Loss of catalytic residue at V164 (P = 0.0151);Loss of catalytic residue at V164 (P = 0.0151);.;Loss of catalytic residue at V164 (P = 0.0151);Loss of catalytic residue at V164 (P = 0.0151);Loss of catalytic residue at V164 (P = 0.0151);Loss of catalytic residue at V164 (P = 0.0151);.;Loss of catalytic residue at V164 (P = 0.0151);Loss of catalytic residue at V164 (P = 0.0151);Loss of catalytic residue at V164 (P = 0.0151);Loss of catalytic residue at V164 (P = 0.0151);Loss of catalytic residue at V164 (P = 0.0151);.;
MVP		0.74
ClinPred		0.94	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.9
Varity_R		0.24
gMVP		0.73

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr16-2105425; COSMIC: COSV54756092; COSMIC: COSV54756092;