16-2071828-C-G

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP3

The NM_000548.5(TSC2):c.1991C>G(p.Ser664Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000188 in 1,597,966 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. S664F) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

TSC2
NM_000548.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 5.63

Publications

1 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: Uncertain_significance. The variant received 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.829

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.1991C>G	p.Ser664Cys	missense	Exon 19 of 42	NP_000539.2
TSC2	NM_001406663.1		c.1991C>G	p.Ser664Cys	missense	Exon 19 of 42	NP_001393592.1
TSC2	NM_001114382.3		c.1991C>G	p.Ser664Cys	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.1991C>G	p.Ser664Cys	missense	Exon 19 of 42	ENSP00000219476.3
TSC2	ENST00000350773.9	TSL:1	c.1991C>G	p.Ser664Cys	missense	Exon 19 of 41	ENSP00000344383.4
TSC2	ENST00000401874.7	TSL:1	c.1991C>G	p.Ser664Cys	missense	Exon 19 of 40	ENSP00000384468.2

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152072

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000138

AC:

AN:

1445894

Hom.:

Cov.:

AF XY:

0.00000139

AC XY:

AN XY:

717852

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33116

American (AMR)

AF:

0.0000231

AC:

AN:

43228

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25716

East Asian (EAS)

AF:

0.00

AC:

AN:

38964

South Asian (SAS)

AF:

0.00

AC:

AN:

83612

European-Finnish (FIN)

AF:

0.00

AC:

AN:

50850

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5744

European-Non Finnish (NFE)

AF:

9.05e-7

AC:

AN:

1104974

Other (OTH)

AF:

0.00

AC:

AN:

59690

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

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:

0.00000658

AC:

AN:

152072

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74280

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

41424

American (AMR)

AF:

0.0000654

AC:

AN:

15280

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5172

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67960

Other (OTH)

AF:

0.00

AC:

AN:

2088

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.325

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Tuberous sclerosis 2

Uncertain:1

Jun 04, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces serine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 664 of the TSC2 protein (p.Ser664Cys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TSC2-related conditions. ClinVar contains an entry for this variant (Variation ID: 467913). 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%. 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.

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

Uncertain:1

Feb 21, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Hereditary cancer-predisposing syndrome

Uncertain:1

Apr 07, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.S664C variant (also known as c.1991C>G), located in coding exon 18 of the TSC2 gene, results from a C to G substitution at nucleotide position 1991. The serine at codon 664 is replaced by cysteine, an amino acid with dissimilar properties. This variant was detected as homozygous in at least one individual (Ambry internal data). 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.

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.27

BayesDel_addAF

Pathogenic

0.33

BayesDel_noAF

Pathogenic

0.23

CADD

Uncertain

(source)

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.78

Eigen

Uncertain

0.52

Eigen_PC

Uncertain

0.40

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.95

M_CAP

Pathogenic

0.32

MetaRNN

Pathogenic

0.83

MetaSVM

Uncertain

0.78

MutationAssessor

Uncertain

2.4

PhyloP100

5.6

PrimateAI

Uncertain

0.65

PROVEAN

Uncertain

-3.2

REVEL

Pathogenic

0.66

Sift

Uncertain

0.012

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.58

MutPred

0.38

Loss of phosphorylation at S664 (P = 0.0069)

MVP

0.87

ClinPred

0.94

GERP RS

5.5

Varity_R

0.31

gMVP

0.60

Mutation Taster

=56/44

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over