Genetic Variant NM_000548.5:c.2072G>T (chr16-2071909-G-T) – ACMG Classification: Likely_benign (-4 pts)

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 2P and 6B. PM1BP4BP6BS2

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. R691H) 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:2B:3

Conservation

PhyloP100: 1.88

Publications

1 publications found

Variant links:

COSMIC-nc: COSV104587122

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

TSC2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

PM1

In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 8 benign, 34 uncertain in NM_000548.5

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 VariationId is 207725.

BS2

High AC in GnomAdExome4 at 21 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000548.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
TSC2	NM_000548.5	MANE Select	c.2072G>T	p.Arg691Leu	missense	Exon 19 of 42	NP_000539.2
TSC2	NM_001406663.1		c.2072G>T	p.Arg691Leu	missense	Exon 19 of 42	NP_001393592.1
TSC2	NM_001114382.3		c.2072G>T	p.Arg691Leu	missense	Exon 19 of 41	NP_001107854.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
TSC2	ENST00000219476.9	TSL:5 MANE Select	c.2072G>T	p.Arg691Leu	missense	Exon 19 of 42	ENSP00000219476.3
TSC2	ENST00000350773.9	TSL:1	c.2072G>T	p.Arg691Leu	missense	Exon 19 of 41	ENSP00000344383.4
TSC2	ENST00000401874.7	TSL:1	c.2072G>T	p.Arg691Leu	missense	Exon 19 of 40	ENSP00000384468.2

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

GnomAD2 exomes

AF:

0.00000961

AC:

AN:

208152

AF XY:

0.00000878

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 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

African (AFR)

AF:

0.00

AC:

AN:

33086

American (AMR)

AF:

0.00

AC:

AN:

42308

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25636

East Asian (EAS)

AF:

0.00

AC:

AN:

38706

South Asian (SAS)

AF:

0.00

AC:

AN:

83266

European-Finnish (FIN)

AF:

0.00

AC:

AN:

50332

Middle Eastern (MID)

AF:

0.000178

AC:

AN:

5614

European-Non Finnish (NFE)

AF:

0.0000172

AC:

AN:

1101660

Other (OTH)

AF:

0.0000168

AC:

AN:

59392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152344

Hom.:

Cov.:

AF XY:

0.0000537

AC XY:

AN XY:

74504

show subpopulations

African (AFR)

AF:

0.0000240

AC:

AN:

41590

American (AMR)

AF:

0.00

AC:

AN:

15312

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5182

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10626

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

68008

Other (OTH)

AF:

0.00

AC:

AN:

2116

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.500

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

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:2Benign:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Tuberous sclerosis 2

Benign:2

Nov 07, 2021

Genome-Nilou Lab

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Oct 16, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Tuberous sclerosis syndrome

Uncertain:1

Mar 04, 2023

All of Us Research Program, National Institutes of Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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

Oct 28, 2022

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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

Benign:1

Aug 06, 2025

Ambry Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.18

BayesDel_addAF

Uncertain

0.11

BayesDel_noAF

Uncertain

-0.080

CADD

Benign

(source)

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.74

Eigen

Benign

-0.38

Eigen_PC

Benign

-0.24

FATHMM_MKL

Uncertain

0.93

LIST_S2

Uncertain

0.89

M_CAP

Uncertain

0.15

MetaRNN

Benign

0.32

MetaSVM

Uncertain

-0.14

MutationAssessor

Benign

0.90

PhyloP100

1.9

PrimateAI

Uncertain

0.50

PROVEAN

Uncertain

-3.0

REVEL

Uncertain

0.55

Sift

Uncertain

0.016

Sift4G

Benign

0.11

Polyphen

0.67

Vest4

0.51

MVP

0.85

ClinPred

0.61

GERP RS

4.5

Varity_R

0.34

gMVP

0.45

Mutation Taster

=95/5

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over