NM_000548.5:c.301G>A

Variant names:

• chr16-2053417-G-A
• rs878854089
• NM_000548.5:c.301G>A

Variant summary

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

The NM_000548.5(TSC2):​c.301G>A​(p.Val101Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000315 in 1,585,430 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000028 (0 hom.)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 9.69

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.301G>A	p.Val101Met	missense_variant	Exon 4 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.301G>A	p.Val101Met	missense_variant	Exon 4 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152238 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000279 AC: 4 AN: 1433192 Hom.: 0 Cov.: 31 AF XY: 0.00000282 AC XY: 2 AN XY: 710302

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000122

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000273

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152238 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74376

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Tuberous sclerosis 2 Uncertain:2

Dec 16, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 101 of the TSC2 protein (p.Val101Met). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TSC2-related conditions. ClinVar contains an entry for this variant (Variation ID: 238006). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt TSC2 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. -

Nov 07, 2021

Genome-Nilou Lab

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Lymphangiomyomatosis;C1846385:Isolated focal cortical dysplasia type II;C1860707:Tuberous sclerosis 2 Uncertain:1

Feb 21, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Uncertain:1

Jun 09, 2022

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; This variant is associated with the following publications: (PMID: 18466115) -

Hereditary cancer-predisposing syndrome Uncertain:1

Dec 03, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.V101M variant (also known as c.301G>A), located in coding exon 3 of the TSC2 gene, results from a G to A substitution at nucleotide position 301. The valine at codon 101 is replaced by methionine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.48
BayesDel_addAF	Pathogenic	0.16	D
BayesDel_noAF	Uncertain	0.0
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.63	D;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.97	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.12	D
MetaRNN	Uncertain	0.62	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	-0.00060	T
MutationAssessor	Uncertain	2.2	M;.;.;.;M;M;.;.;M;.;.;M;.;.;.
PrimateAI	Uncertain	0.77	T
PROVEAN	Benign	-1.7	N;.;.;N;.;N;.;.;N;.;.;.;.;.;N
REVEL	Uncertain	0.49
Sift	Uncertain	0.0090	D;.;.;D;.;D;.;.;D;.;.;.;.;.;D
Sift4G	Uncertain	0.0090	D;.;.;D;.;D;.;.;D;.;.;.;.;.;D
Polyphen		1.0	D;.;.;.;.;D;.;.;D;.;.;.;.;.;.
Vest4		0.79
MutPred		0.42		Gain of catalytic residue at V101 (P = 0.0077);Gain of catalytic residue at V101 (P = 0.0077);Gain of catalytic residue at V101 (P = 0.0077);.;Gain of catalytic residue at V101 (P = 0.0077);Gain of catalytic residue at V101 (P = 0.0077);Gain of catalytic residue at V101 (P = 0.0077);Gain of catalytic residue at V101 (P = 0.0077);Gain of catalytic residue at V101 (P = 0.0077);.;Gain of catalytic residue at V101 (P = 0.0077);Gain of catalytic residue at V101 (P = 0.0077);Gain of catalytic residue at V101 (P = 0.0077);Gain of catalytic residue at V101 (P = 0.0077);.;
MVP		0.64
ClinPred		0.93	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.22
gMVP		0.76

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

Publications

LitVar

Other links and lift over

dbSNP: rs878854089; hg19: chr16-2103418;