16-2071909-G-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4BP6

The NM_000548.5(TSC2):c.2072G>T(p.Arg691Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000157 in 1,592,344 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R691C) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

TSC2
NM_000548.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:2

Conservation

PhyloP100: 1.88

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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.31786093).

BP6

Variant 16-2071909-G-T is Benign according to our data. Variant chr16-2071909-G-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 207725.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=3, Likely_benign=1, Benign=1}. Variant chr16-2071909-G-T is described in Lovd as [Likely_benign].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TSC2	NM_000548.5 linkuse as main transcript	c.2072G>T	p.Arg691Leu	missense_variant	19/42	ENST00000219476.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TSC2	ENST00000219476.9 linkuse as main transcript	c.2072G>T	p.Arg691Leu	missense_variant	19/42	5	NM_000548.5		P49815-1

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152226

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000961

AC:

AN:

208152

Hom.:

AF XY:

0.00000878

AC XY:

AN XY:

113942

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000224

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000146

AC:

AN:

1440000

Hom.:

Cov.:

AF XY:

0.0000182

AC XY:

AN XY:

714356

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:

0.0000172

Gnomad4 OTH exome

AF:

0.0000168

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152344

Hom.:

Cov.:

AF XY:

0.0000537

AC XY:

AN XY:

74504

show subpopulations

Gnomad4 AFR

AF:

0.0000240

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:

0.0000441

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000151

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000117

AC:

ExAC

AF:

0.0000250

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Tuberous sclerosis 2

Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -
Benign, criteria provided, single submitter	clinical testing	Invitae	Jan 18, 2024	- -

Tuberous sclerosis syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Mar 04, 2023

This missense variant replaces arginine with leucine at codon 691 of the TSC2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with tuberous sclerosis complex in the literature. This variant has been identified in 3/239524 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 28, 2022

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 31925297) -

Hereditary cancer-predisposing syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 20, 2023

The p.R691L variant (also known as c.2072G>T), located in coding exon 18 of the TSC2 gene, results from a G to T substitution at nucleotide position 2072. The arginine at codon 691 is replaced by leucine, an amino acid with dissimilar properties. This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. 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

Benign

0.18

BayesDel_addAF

Uncertain

0.11

BayesDel_noAF

Uncertain

-0.080

Cadd

Benign

Dann

Uncertain

0.99

DEOGEN2

Uncertain

0.74

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

Eigen

Benign

-0.38

Eigen_PC

Benign

-0.24

FATHMM_MKL

Uncertain

0.93

LIST_S2

Uncertain

0.89

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

M_CAP

Uncertain

0.15

MetaRNN

Benign

0.32

T;T;T;T;T;T;T;T;T;T;T;T;T;T;T

MetaSVM

Uncertain

-0.14

MutationAssessor

Benign

0.90

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

MutationTaster

Benign

0.63

N;N;N;N;N;N;N

PrimateAI

Uncertain

0.50

PROVEAN

Uncertain

-3.0

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

REVEL

Uncertain

0.55

Sift

Uncertain

0.016

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

Sift4G

Benign

0.11

T;.;.;T;.;T;.;.;T;T;.;.;.;.;T

Polyphen

0.67

P;.;.;.;B;B;.;.;B;B;.;.;.;.;.

Vest4

0.51

MVP

0.85

ClinPred

0.61

GERP RS

4.5

Varity_R

0.34

gMVP

0.45

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over