Genetic Variant TSC2:p.Val766Leu (chr16-2072924-G-T) – ACMG Classification: Likely_pathogenic (6 pts)

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PM5PP3_Moderate

The NM_000548.5(TSC2):c.2296G>T(p.Val766Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,260 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. V766M) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

TSC2
NM_000548.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.87

Variant links:

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 links:

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr16-2072924-G-A is described in Lovd as [Likely_pathogenic].

PP3

MetaRNN computational evidence supports a deleterious effect, 0.84

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5 link	c.2296G>T	p.Val766Leu	missense_variant	Exon 21 of 42	ENST00000219476.9	NP_000539.2	P49815-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9 link	c.2296G>T	p.Val766Leu	missense_variant	Exon 21 of 42	5	NM_000548.5	ENSP00000219476.3		P49815-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1461260

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

726898

show subpopulations

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:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000180

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome

Uncertain:1

Aug 30, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.V766L variant (also known as c.2296G>T), located in coding exon 20 of the TSC2 gene, results from a G to T substitution at nucleotide position 2296. The valine at codon 766 is replaced by leucine, an amino acid with highly similar properties. This amino acid position is conserved. 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

Uncertain

0.54

BayesDel_addAF

Pathogenic

0.33

BayesDel_noAF

Pathogenic

0.24

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.75

D;.;.;.;.;.;.;.;.;.;.;.;D;.;D

Eigen

Uncertain

0.67

Eigen_PC

Pathogenic

0.69

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.91

D;D;D;D;D;D;D;D;D;D;D;D;D;D;D

M_CAP

Benign

0.061

MetaRNN

Pathogenic

0.84

D;D;D;D;D;D;D;D;D;D;D;D;D;D;D

MetaSVM

Uncertain

0.40

MutationAssessor

Benign

1.7

L;.;.;.;L;L;.;.;.;L;.;L;.;.;.

PrimateAI

Uncertain

0.73

PROVEAN

Uncertain

-2.4

N;.;.;N;.;N;.;.;N;N;.;.;.;.;N

REVEL

Pathogenic

0.72

Sift

Uncertain

0.0040

D;.;.;D;.;D;.;.;D;D;.;.;.;.;D

Sift4G

Uncertain

0.018

D;.;.;D;.;D;.;.;D;D;.;.;.;.;D

Polyphen

0.99

D;.;.;.;D;D;.;.;D;P;.;.;.;.;.

Vest4

0.77

MutPred

0.66

Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);.;Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);.;Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);.;

MVP

0.91

ClinPred

0.77

GERP RS

5.7

Varity_R

0.65

gMVP

0.60

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over