rs778040604

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PM2PP3

The NM_000548.5(TSC2):​c.2122C>A​(p.Leu708Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,754 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 variant affecting the same amino acid position, but resulting in a different missense (i.e. L708P) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

TSC2
NM_000548.5 missense

Scores

3
10
6

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:1

Conservation

PhyloP100: 1.78

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 38 uncertain in NM_000548.5
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.82

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TSC2NM_000548.5 linkc.2122C>A p.Leu708Met missense_variant Exon 20 of 42 ENST00000219476.9 NP_000539.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TSC2ENST00000219476.9 linkc.2122C>A p.Leu708Met missense_variant Exon 20 of 42 5 NM_000548.5 ENSP00000219476.3

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251202
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000867
Gnomad ASJ exome
AF:
0.00
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:
0.00000205
AC:
3
AN:
1461754
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727158
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000671
AC:
3
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53292
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1112006
Other (OTH)
AF:
0.00
AC:
0
AN:
60390
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
33
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:4Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Tuberous sclerosis 2 Uncertain:1Benign:1
Oct 23, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Nov 07, 2021
Genome-Nilou Lab
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Jul 08, 2019
Athena Diagnostics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Isolated focal cortical dysplasia type II Uncertain:1
Jun 10, 2021
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hereditary cancer-predisposing syndrome Uncertain:1
Feb 06, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.L708M variant (also known as c.2122C>A), located in coding exon 19 of the TSC2 gene, results from a C to A substitution at nucleotide position 2122. The leucine at codon 708 is replaced by methionine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.17
BayesDel_addAF
Uncertain
0.093
D
BayesDel_noAF
Uncertain
0.090
CADD
Benign
22
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.58
D;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen
Uncertain
0.22
Eigen_PC
Benign
0.16
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Benign
0.83
T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
M_CAP
Pathogenic
0.40
D
MetaRNN
Pathogenic
0.82
D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM
Uncertain
0.62
D
MutationAssessor
Uncertain
2.3
M;.;.;.;M;M;.;.;.;M;.;M;.;.;.
PhyloP100
1.8
PrimateAI
Uncertain
0.68
T
PROVEAN
Benign
-1.3
N;.;.;N;.;N;.;.;N;N;.;.;.;.;N
REVEL
Pathogenic
0.70
Sift
Uncertain
0.0090
D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Sift4G
Benign
0.11
T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Polyphen
1.0
D;.;.;.;D;P;.;.;D;P;.;.;.;.;.
Vest4
0.76
MutPred
0.76
Loss of methylation at K707 (P = 0.0526);Loss of methylation at K707 (P = 0.0526);Loss of methylation at K707 (P = 0.0526);.;Loss of methylation at K707 (P = 0.0526);Loss of methylation at K707 (P = 0.0526);Loss of methylation at K707 (P = 0.0526);Loss of methylation at K707 (P = 0.0526);.;Loss of methylation at K707 (P = 0.0526);Loss of methylation at K707 (P = 0.0526);Loss of methylation at K707 (P = 0.0526);Loss of methylation at K707 (P = 0.0526);Loss of methylation at K707 (P = 0.0526);.;
MVP
0.87
ClinPred
0.77
D
GERP RS
4.2
Varity_R
0.24
gMVP
0.32
Mutation Taster
=53/47
polymorphism

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

Other links and lift over

dbSNP: rs778040604; hg19: chr16-2122266; API