NM_000548.5:c.4998C>A

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 6P and 5B. PM1PP3_StrongBP6BS2

The NM_000548.5(TSC2):c.4998C>A(p.Phe1666Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,612,304 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 Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely benign in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. F1666V) has been classified as Uncertain significance.

Frequency

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

Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

TSC2
NM_000548.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:2

Conservation

PhyloP100: 2.28

Publications

3 publications found

Variant links:

COSMIC-nc: COSV51922542

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 1 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 10 benign, 46 uncertain in NM_000548.5

PP3

MetaRNN computational evidence supports a deleterious effect, 0.98

BP6

Variant 16-2087871-C-A is Benign according to our data. Variant chr16-2087871-C-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 207690.

BS2

High AC in GnomAdExome4 at 6 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5 link	c.4998C>A	p.Phe1666Leu	missense_variant	Exon 39 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.4998C>A	p.Phe1666Leu	missense_variant	Exon 39 of 42	5	NM_000548.5	ENSP00000219476.3		P49815-1

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152076

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.000288

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

GnomAD2 exomes

AF:

0.00000801

AC:

AN:

249546

AF XY:

0.00000738

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.000200

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000411

AC:

AN:

1460228

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

726392

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33446

American (AMR)

AF:

0.00

AC:

AN:

44706

Ashkenazi Jewish (ASJ)

AF:

0.000191

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39564

South Asian (SAS)

AF:

0.00

AC:

AN:

86220

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52104

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1111912

Other (OTH)

AF:

0.00

AC:

AN:

60372

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:

0.00000658

AC:

AN:

152076

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74266

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41368

American (AMR)

AF:

0.00

AC:

AN:

15278

Ashkenazi Jewish (ASJ)

AF:

0.000288

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5164

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68020

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

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:

0.0000282

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.00000826

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome

Uncertain:2

Apr 16, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.F1666L variant (also known as c.4998C>A), located in coding exon 38 of the TSC2 gene, results from a C to A substitution at nucleotide position 4998. The phenylalanine at codon 1666 is replaced by leucine, an amino acid with highly similar properties. 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. -

Jan 12, 2022

Sema4, Sema4

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:curation

- -

Tuberous sclerosis 2

Benign:2

Nov 07, 2021

Genome-Nilou Lab

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 17, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Tuberous sclerosis syndrome

Uncertain:1

Jun 09, 2024

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 phenylalanine with leucine at codon 1666 of the TSC2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 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 TSC2-related disorders in the literature. This variant has been identified in 3/280940 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. -

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

Uncertain:1

Feb 12, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Uncertain:1

Mar 05, 2020

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 -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

1.0

BayesDel_addAF

Pathogenic

0.51

BayesDel_noAF

Pathogenic

0.49

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.95

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

Eigen

Uncertain

0.64

Eigen_PC

Uncertain

0.56

FATHMM_MKL

Uncertain

0.91

LIST_S2

Uncertain

0.94

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

M_CAP

Pathogenic

0.73

MetaRNN

Pathogenic

0.98

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

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

3.3

M;.;.;.;.;.;.;.;.;.;.;.;.;.;.

PhyloP100

2.3

PrimateAI

Pathogenic

0.89

PROVEAN

Pathogenic

-5.1

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

REVEL

Pathogenic

0.91

Sift

Uncertain

0.0060

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

Sift4G

Pathogenic

0.0

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

Polyphen

0.99

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

Vest4

0.88

MutPred

0.93

Loss of sheet (P = 0.1158);.;.;.;.;.;.;.;.;.;.;.;.;.;.;

MVP

0.98

ClinPred

0.98

GERP RS

4.6

Varity_R

0.84

gMVP

0.85

Mutation Taster

=19/81

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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