chr16-2062994-C-T

Variant names:

• chr16-2062994-C-T
• rs397515261
• NM_000548.5:c.1384C>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 6P and 4B. PM1 PP3_Strong BS2

The NM_000548.5(TSC2):​c.1384C>T​(p.Arg462Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000786 in 1,398,850 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. R462H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000079 (0 hom.)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3 O:1
• Conservation: PhyloP100: 4.41
• Publications: 8 publications found

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]

TSC2 Gene-Disease associations (from GenCC):

• tuberous sclerosis

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• tuberous sclerosis 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, Ambry Genetics
• 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 2 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 8 benign, 14 uncertain in NM_000548.5
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.954
• BS2: High AC in GnomAdExome4 at 11 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.1384C>T	p.Arg462Cys	missense_variant	Exon 14 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.1384C>T	p.Arg462Cys	missense_variant	Exon 14 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000786 AC: 11 AN: 1398850 Hom.: 0 Cov.: 31 AF XY: 0.00000435 AC XY: 3 AN XY: 689958

African (AFR) AF: 0.00 AC: 0 AN: 31590

American (AMR) AF: 0.00 AC: 0 AN: 35702

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25172

East Asian (EAS) AF: 0.00 AC: 0 AN: 35732

South Asian (SAS) AF: 0.0000126 AC: 1 AN: 79232

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 49004

Middle Eastern (MID) AF: 0.000179 AC: 1 AN: 5596

European-Non Finnish (NFE) AF: 0.00000834 AC: 9 AN: 1078846

Other (OTH) AF: 0.00 AC: 0 AN: 57976

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Tuberous sclerosis 2 Uncertain:1

May 13, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 462 of the TSC2 protein (p.Arg462Cys). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with tuberous sclerosis (PMID: 21520333, 22903760). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 65350). 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 with a negative predictive value of 95%. Experimental studies have shown that this missense change affects TSC2 function (PMID: 22903760). 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. -

not provided Uncertain:1

Dec 19, 2024

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 has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 22903760) -

Hereditary cancer-predisposing syndrome Uncertain:1

Jan 31, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R462C variant (also known as c.1384C>T), located in coding exon 13 of the TSC2 gene, results from a C to T substitution at nucleotide position 1384. The arginine at codon 462 is replaced by cysteine, an amino acid with highly dissimilar properties. This variant has been reported in an individual meeting diagnostic criteria for tuberous sclerosis; this variant demonstrated intermediate loss of the TSC1-TSC2 dependent inhibition of TORC1 and was associated with reduced TSC1 signals in functional studies performed (Hoogeveen-Westerveld M et al. Hum Mutat, 2013 Jan;34:167-75). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Tuberous sclerosis syndrome Other:1

-

Tuberous sclerosis database (TSC2)

Significance: not provided

Review Status: no classification provided

Collection Method: curation

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.91
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.35
CADD	Pathogenic	32
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.95	D;.;.;.;.;.;.;.;.;.;.;.;D;.;D
Eigen	Pathogenic	0.73
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Uncertain	0.85	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.37	D
MetaRNN	Pathogenic	0.95	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.28	D
MutationAssessor	Uncertain	2.7	M;.;.;.;M;M;.;.;.;M;.;M;.;.;.
PhyloP100		4.4
PrimateAI	Pathogenic	0.81	D
PROVEAN	Pathogenic	-7.0	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
REVEL	Pathogenic	0.81
Sift	Uncertain	0.0010	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Sift4G	Uncertain	0.0040	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Polyphen		0.99	D;.;.;.;D;D;.;.;D;D;.;.;.;.;.
Vest4		0.99
MutPred		0.79		Loss of MoRF binding (P = 0.0071);Loss of MoRF binding (P = 0.0071);Loss of MoRF binding (P = 0.0071);.;Loss of MoRF binding (P = 0.0071);Loss of MoRF binding (P = 0.0071);Loss of MoRF binding (P = 0.0071);Loss of MoRF binding (P = 0.0071);.;Loss of MoRF binding (P = 0.0071);Loss of MoRF binding (P = 0.0071);Loss of MoRF binding (P = 0.0071);Loss of MoRF binding (P = 0.0071);Loss of MoRF binding (P = 0.0071);.;
MVP		0.97
ClinPred		0.99	D
GERP RS		5.2
PromoterAI		-0.027	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.74
gMVP		0.88
Mutation Taster		=41/59	disease causing

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

Other links and lift over

dbSNP: rs397515261; hg19: chr16-2112995; COSMIC: COSV54761376; COSMIC: COSV54761376;