16-2053371-C-T

Variant names:

Variant summary

Our verdict is Benign. The variant received -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_000548.5(TSC2):c.255C>T(p.Val85Val) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00124 in 1,590,176 control chromosomes in the GnomAD database, including 4 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.00081 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0013 ( 4 hom. )

Consequence

TSC2
NM_000548.5 synonymous

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:23O:1

Conservation

PhyloP100: -1.30

Publications

9 publications found

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 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: Benign. The variant received -21 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.75).

BP6

Variant 16-2053371-C-T is Benign according to our data. Variant chr16-2053371-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 49572.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BP7

Synonymous conserved (PhyloP=-1.3 with no splicing effect.

BS1

Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.000807 (123/152340) while in subpopulation NFE AF = 0.00123 (84/68036). AF 95% confidence interval is 0.00102. There are 0 homozygotes in GnomAd4. There are 57 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.

BS2

High AC in GnomAd4 at 123 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5 link	c.255C>T	p.Val85Val	synonymous_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 link	c.255C>T	p.Val85Val	synonymous_variant	Exon 4 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes

AF:

0.000808

AC:

123

AN:

152222

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000314

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000851

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000414

Gnomad FIN

AF:

0.000941

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00123

Gnomad OTH

AF:

0.000478

GnomAD2 exomes

AF:

0.00118

AC:

248

AN:

209850

AF XY:

0.00110

show subpopulations

Gnomad AFR exome

AF:

0.000634

Gnomad AMR exome

AF:

0.000980

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00159

Gnomad NFE exome

AF:

0.00177

Gnomad OTH exome

AF:

0.00114

GnomAD4 exome

AF:

0.00129

AC:

1853

AN:

1437836

Hom.:

Cov.:

AF XY:

0.00124

AC XY:

886

AN XY:

713026

show subpopulations

African (AFR)

AF:

0.000363

AC:

AN:

33078

American (AMR)

AF:

0.000988

AC:

AN:

41492

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25642

East Asian (EAS)

AF:

0.00

AC:

AN:

38572

South Asian (SAS)

AF:

0.000353

AC:

AN:

82234

European-Finnish (FIN)

AF:

0.00112

AC:

AN:

50862

Middle Eastern (MID)

AF:

0.00193

AC:

AN:

5176

European-Non Finnish (NFE)

AF:

0.00146

AC:

1604

AN:

1101376

Other (OTH)

AF:

0.00168

AC:

100

AN:

59404

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.460

Heterozygous variant carriers

101

201

302

402

503

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

100

150

200

250

<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:

0.000807

AC:

123

AN:

152340

Hom.:

Cov.:

AF XY:

0.000765

AC XY:

AN XY:

74490

show subpopulations

African (AFR)

AF:

0.000313

AC:

AN:

41570

American (AMR)

AF:

0.000849

AC:

AN:

15304

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5180

South Asian (SAS)

AF:

0.000414

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.000941

AC:

AN:

10626

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00123

AC:

AN:

68036

Other (OTH)

AF:

0.000473

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.494

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:

0.00134

Hom.:

Bravo

AF:

0.000865

Asia WGS

AF:

0.000577

AC:

AN:

3478

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:23Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:7

Aug 14, 2021

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Feb 12, 2016

Eurofins Ntd Llc (ga)

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Oct 08, 2018

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: TSC2 c.255C>T alters a non-conserved nucleotide resulting in a synonymous change. 5/5 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.0011 in 235020 control chromosomes (gnomAD). The observed variant frequency is approximately 16-folds higher than the estimated maximal expected allele frequency for a pathogenic variant in TSC2 causing Tuberous Sclerosis Complex phenotype (6.9e-05), strongly suggesting that the variant is benign. To our knowledge, no occurrence of c.255C>T in individuals affected with Tuberous Sclerosis Complex and no experimental evidence demonstrating its impact on protein function have been reported. Four ClinVar submissions from clinical diagnostic laboratories (evaluation after 2014) cites the variant as likely benign/benign. Based on the evidence outlined above, the variant was classified as benign.

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance:Benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

PreventionGenetics, part of Exact Sciences

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Apr 01, 2013

GeneDx

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease.

Feb 21, 2013

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Val85Val in exon 4 of TSC2: This variant is not expected to have clinical significance because it does not alter an amino acid residue and is not located within the splice consensus sequence. It has been identified in 0.2% (16/8582) of European American chromosomes from a broad population by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS; dbSNP rs45517098).

Tuberous sclerosis 2

Benign:5

May 02, 2025

Myriad Genetics, Inc.

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant is considered benign. This variant is a silent/synonymous amino acid change and it is not expected to impact splicing.

May 30, 2017

Athena Diagnostics

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Jul 07, 2023

KCCC/NGS Laboratory, Kuwait Cancer Control Center

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Feb 04, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Nov 07, 2021

Genome-Nilou Lab

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

not provided

Benign:5

Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

Clinical Genetics, Academic Medical Center

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

Sep 24, 2024

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Breakthrough Genomics, Breakthrough Genomics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:not provided

Sep 01, 2025

CeGaT Center for Human Genetics Tuebingen

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

TSC2: BP4, BP7

Tuberous sclerosis syndrome

Benign:3Other:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease.

Tuberous sclerosis database (TSC2)

Significance:not provided

Review Status:no classification provided

Collection Method:curation

Sep 16, 2022

Color Diagnostics, LLC DBA Color Health

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Feb 05, 2024

All of Us Research Program, National Institutes of Health

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Hereditary cancer-predisposing syndrome

Benign:2

Oct 30, 2020

Sema4, Sema4

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:curation

Oct 07, 2014

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.

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

Benign:1

Oct 13, 2021

Department of Pathology and Laboratory Medicine, Sinai Health System

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.75

CADD

Benign

0.29

(source)

DANN

Benign

0.55

PhyloP100

-1.3

PromoterAI

0.0056

Neutral

(source)

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Mutation Taster

=99/1

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.030

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

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over