rs558292668

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1PM2

The NM_000548.5(TSC2):​c.2070C>A​(p.Phe690Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★). 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. F690V) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

TSC2
NM_000548.5 missense

Scores

3
8
8

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 0.473

Publications

0 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 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 11 benign, 33 uncertain in NM_000548.5
PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TSC2NM_000548.5 linkc.2070C>A p.Phe690Leu missense_variant Exon 19 of 42 ENST00000219476.9 NP_000539.2 P49815-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TSC2ENST00000219476.9 linkc.2070C>A p.Phe690Leu missense_variant Exon 19 of 42 5 NM_000548.5 ENSP00000219476.3 P49815-1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
Data not reliable, filtered out with message: AC0
AF:
0.00
AC:
0
AN:
1441534
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
715286
African (AFR)
AF:
0.00
AC:
0
AN:
33122
American (AMR)
AF:
0.00
AC:
0
AN:
42566
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25656
East Asian (EAS)
AF:
0.00
AC:
0
AN:
38746
South Asian (SAS)
AF:
0.00
AC:
0
AN:
83426
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
50506
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5630
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1102414
Other (OTH)
AF:
0.00
AC:
0
AN:
59468
GnomAD4 genome
Cov.:
33

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Tuberous sclerosis 2 Uncertain:1
Nov 22, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with TSC2-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces phenylalanine with leucine at codon 690 of the TSC2 protein (p.Phe690Leu). The phenylalanine residue is moderately conserved and there is a small physicochemical difference between phenylalanine and leucine. -

Hereditary cancer-predisposing syndrome Uncertain:1
Nov 17, 2020
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.F690L variant (also known as c.2070C>A), located in coding exon 18 of the TSC2 gene, results from a C to A substitution at nucleotide position 2070. The phenylalanine at codon 690 is replaced by leucine, 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. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.97
BayesDel_addAF
Pathogenic
0.20
D
BayesDel_noAF
Uncertain
0.050
CADD
Benign
16
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.65
D;.;.;.;.;.;.;.;.;.;.;.;D;.;D
Eigen
Benign
-0.67
Eigen_PC
Benign
-0.58
FATHMM_MKL
Uncertain
0.80
D
LIST_S2
Uncertain
0.90
D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP
Benign
0.075
D
MetaRNN
Uncertain
0.46
T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM
Benign
-0.66
T
MutationAssessor
Benign
1.2
L;.;.;.;L;L;.;.;.;L;.;L;.;.;.
PhyloP100
0.47
PrimateAI
Pathogenic
0.80
T
PROVEAN
Uncertain
-2.4
N;.;.;N;.;N;.;.;N;N;.;.;.;.;N
REVEL
Uncertain
0.60
Sift
Benign
0.16
T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Sift4G
Benign
0.085
T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Polyphen
0.090
B;.;.;.;B;B;.;.;B;B;.;.;.;.;.
Vest4
0.55
MutPred
0.54
Gain of disorder (P = 0.0373);Gain of disorder (P = 0.0373);Gain of disorder (P = 0.0373);.;Gain of disorder (P = 0.0373);Gain of disorder (P = 0.0373);Gain of disorder (P = 0.0373);Gain of disorder (P = 0.0373);.;Gain of disorder (P = 0.0373);Gain of disorder (P = 0.0373);Gain of disorder (P = 0.0373);Gain of disorder (P = 0.0373);Gain of disorder (P = 0.0373);.;
MVP
0.86
ClinPred
0.81
D
GERP RS
0.74
Varity_R
0.55
gMVP
0.61
Mutation Taster
=69/31
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: rs558292668; hg19: chr16-2121908; API