16-2053345-G-T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_000548.5(TSC2):c.229G>T(p.Ala77Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000007 in 1,428,980 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. A77T) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 7.0e-7 ( 0 hom. )

Consequence

TSC2
NM_000548.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 9.61

Publications

3 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 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5 link	c.229G>T	p.Ala77Ser	missense_variant	Exon 4 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.229G>T	p.Ala77Ser	missense_variant	Exon 4 of 42	5	NM_000548.5	ENSP00000219476.3		P49815-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

7.00e-7

AC:

AN:

1428980

Hom.:

Cov.:

AF XY:

0.00000141

AC XY:

AN XY:

707850

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

32844

American (AMR)

AF:

0.00

AC:

AN:

39984

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25504

East Asian (EAS)

AF:

0.00

AC:

AN:

38086

South Asian (SAS)

AF:

0.00

AC:

AN:

81346

European-Finnish (FIN)

AF:

0.00

AC:

AN:

50532

Middle Eastern (MID)

AF:

0.00

AC:

AN:

4860

European-Non Finnish (NFE)

AF:

9.12e-7

AC:

AN:

1096734

Other (OTH)

AF:

0.00

AC:

AN:

59090

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

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome

Uncertain:2

Dec 13, 2021

Sema4, Sema4

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:curation

- -

Dec 22, 2021

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.A77S variant (also known as c.229G>T), located in coding exon 3 of the TSC2 gene, results from a G to T substitution at nucleotide position 229. The alanine at codon 77 is replaced by serine, an amino acid with similar properties. This amino acid position is highly 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. -

Tuberous sclerosis 2

Uncertain:1

Dec 18, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 77 of the TSC2 protein (p.Ala77Ser). 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: 968409). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) 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

May 01, 2022

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.27

BayesDel_addAF

Pathogenic

0.20

BayesDel_noAF

Uncertain

0.050

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.50

D;.;.;.;.;.;.;.;.;.;.;T;.;T

Eigen

Uncertain

0.60

Eigen_PC

Uncertain

0.58

FATHMM_MKL

Pathogenic

1.0

LIST_S2

Uncertain

0.95

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

M_CAP

Pathogenic

0.44

MetaRNN

Uncertain

0.68

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

MetaSVM

Uncertain

-0.024

MutationAssessor

Benign

1.9

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

PhyloP100

9.6

PrimateAI

Uncertain

0.75

PROVEAN

Benign

-1.8

N;.;.;N;.;N;.;.;N;.;.;.;.;N

REVEL

Uncertain

0.55

Sift

Uncertain

0.0080

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

Sift4G

Uncertain

0.017

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

Polyphen

1.0

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

Vest4

0.70

MutPred

0.39

Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);.;Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);.;

MVP

0.74

ClinPred

0.91

GERP RS

4.8

PromoterAI

-0.014

Neutral

(source)

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.25

gMVP

0.42

Mutation Taster

=47/53

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

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

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over