rs1318274503

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1PP3_Moderate

The NM_000548.5(TSC2):​c.828G>A​(p.Met276Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000387 in 1,551,676 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 Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M276T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

TSC2
NM_000548.5 missense

Scores

8
9
1

Clinical Significance

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

Conservation

PhyloP100: 7.67

Publications

2 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 4 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 6 benign, 42 uncertain in NM_000548.5
PP3
MetaRNN computational evidence supports a deleterious effect, 0.868

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

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TSC2
NM_000548.5
MANE Select
c.828G>Ap.Met276Ile
missense
Exon 9 of 42NP_000539.2
TSC2
NM_001406689.1
c.-604G>A
5_prime_UTR_premature_start_codon_gain
Exon 9 of 42NP_001393618.1
TSC2
NM_001406690.1
c.-604G>A
5_prime_UTR_premature_start_codon_gain
Exon 9 of 42NP_001393619.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TSC2
ENST00000219476.9
TSL:5 MANE Select
c.828G>Ap.Met276Ile
missense
Exon 9 of 42ENSP00000219476.3
TSC2
ENST00000350773.9
TSL:1
c.828G>Ap.Met276Ile
missense
Exon 9 of 41ENSP00000344383.4
TSC2
ENST00000401874.7
TSL:1
c.828G>Ap.Met276Ile
missense
Exon 9 of 40ENSP00000384468.2

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152180
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000965
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.00000143
AC:
2
AN:
1399496
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
690284
show subpopulations
African (AFR)
AF:
0.0000633
AC:
2
AN:
31602
American (AMR)
AF:
0.00
AC:
0
AN:
35720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25184
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35742
South Asian (SAS)
AF:
0.00
AC:
0
AN:
79264
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
49230
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5682
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1079052
Other (OTH)
AF:
0.00
AC:
0
AN:
58020
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.0000263
AC:
4
AN:
152180
Hom.:
0
Cov.:
32
AF XY:
0.0000404
AC XY:
3
AN XY:
74338
show subpopulations
African (AFR)
AF:
0.0000965
AC:
4
AN:
41432
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68022
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.563
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.00
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
Nov 07, 2021
Genome-Nilou Lab
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Dec 15, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Tuberous sclerosis syndrome Uncertain:1
Mar 04, 2023
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 methionine with isoleucine at codon 276 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 tuberous sclerosis complex in the literature. This variant has been identified in 1/31376 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.

not provided Uncertain:1
May 13, 2021
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

Hereditary cancer-predisposing syndrome Uncertain:1
Sep 09, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.M276I variant (also known as c.828G>A), located in coding exon 8 of the TSC2 gene, results from a G to A substitution at nucleotide position 828. The methionine at codon 276 is replaced by isoleucine, 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. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.92
BayesDel_addAF
Pathogenic
0.33
D
BayesDel_noAF
Pathogenic
0.24
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.78
D
Eigen
Pathogenic
0.70
Eigen_PC
Uncertain
0.62
FATHMM_MKL
Uncertain
0.97
D
LIST_S2
Uncertain
0.91
D
M_CAP
Pathogenic
0.64
D
MetaRNN
Pathogenic
0.87
D
MetaSVM
Uncertain
0.43
D
MutationAssessor
Uncertain
2.3
M
PhyloP100
7.7
PrimateAI
Uncertain
0.68
T
PROVEAN
Uncertain
-3.3
D
REVEL
Pathogenic
0.77
Sift
Benign
0.076
T
Sift4G
Pathogenic
0.0
D
Polyphen
0.89
P
Vest4
0.83
MutPred
0.62
Gain of helix (P = 0.2294)
MVP
0.78
ClinPred
0.98
D
GERP RS
4.7
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.59
gMVP
0.79
Mutation Taster
=16/84
disease causing

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: rs1318274503; hg19: chr16-2107159; COSMIC: COSV105872694; API