16-2088317-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 5P and 4B. PM1PM5PP3BS2

The NM_000548.5(TSC2):​c.5251C>T​(p.Arg1751Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000026 in 1,612,592 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. R1751H) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 34)
Exomes 𝑓: 0.000027 ( 0 hom. )

Consequence

TSC2
NM_000548.5 missense

Scores

14
3
2

Clinical Significance

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

Conservation

PhyloP100: 1.28
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PM1
In a domain Rap-GAP (size 227) in uniprot entity TSC2_HUMAN there are 284 pathogenic changes around while only 47 benign (86%) in NM_000548.5
PM5
Other missense variant is known to change same aminoacid residue: Variant chr16-2088318-G-A is described in Lovd as [Likely_pathogenic].
PP3
MetaRNN computational evidence supports a deleterious effect, 0.824
BS2
High AC in GnomAdExome4 at 39 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TSC2NM_000548.5 linkc.5251C>T p.Arg1751Cys missense_variant Exon 41 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.5251C>T p.Arg1751Cys missense_variant Exon 41 of 42 5 NM_000548.5 ENSP00000219476.3 P49815-1

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152226
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000321
AC:
8
AN:
249408
Hom.:
0
AF XY:
0.0000443
AC XY:
6
AN XY:
135432
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000579
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.0000327
Gnomad FIN exome
AF:
0.0000466
Gnomad NFE exome
AF:
0.0000356
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000267
AC:
39
AN:
1460366
Hom.:
0
Cov.:
35
AF XY:
0.0000206
AC XY:
15
AN XY:
726464
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000447
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000504
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.0000193
Gnomad4 NFE exome
AF:
0.0000279
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152226
Hom.:
0
Cov.:
34
AF XY:
0.0000269
AC XY:
2
AN XY:
74364
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000441
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000282
Hom.:
0
Bravo
AF:
0.0000264
ExAC
AF:
0.0000247
AC:
3
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:5
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:1
Nov 03, 2021
Institute for Clinical Genetics, University Hospital TU Dresden, University Hospital TU Dresden
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Feb 18, 2021
GeneDx
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Missense variants in nearby residues reported in the Human Gene Mutation Database (Stenson et al., 2014); Has not been previously published as pathogenic or benign in association with a neurodevelopmental phenotype to our knowledge; This variant is associated with the following publications: (PMID: 29395620, 29167182, 24631838) -

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 12, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Tuberous sclerosis syndrome Uncertain:1
Dec 18, 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 arginine with cysteine at codon 1751 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 8/249408 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. -

TSC2-related disorder Benign:1
Dec 19, 2023
PreventionGenetics, part of Exact Sciences
Significance: Likely benign
Review Status: no assertion criteria provided
Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Hereditary cancer-predisposing syndrome Benign:1
Jan 17, 2023
Ambry Genetics
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.80
BayesDel_addAF
Pathogenic
0.32
D
BayesDel_noAF
Pathogenic
0.39
CADD
Pathogenic
31
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.94
D;.;.;.;.;.;.;.;.;.;.;.;D;.;D
Eigen
Uncertain
0.49
Eigen_PC
Uncertain
0.36
FATHMM_MKL
Benign
0.75
D
LIST_S2
Pathogenic
0.99
D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP
Pathogenic
0.70
D
MetaRNN
Pathogenic
0.82
D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM
Pathogenic
0.96
D
MutationAssessor
Pathogenic
3.3
M;.;.;.;.;.;.;.;.;.;.;.;.;.;.
PrimateAI
Uncertain
0.61
T
PROVEAN
Pathogenic
-6.8
D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
REVEL
Pathogenic
0.84
Sift
Pathogenic
0.0
D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Sift4G
Pathogenic
0.0
D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Polyphen
1.0
D;.;.;.;D;D;.;.;D;D;.;.;.;.;.
Vest4
0.66
MutPred
0.50
Loss of MoRF binding (P = 0.052);.;.;.;.;.;.;.;.;.;.;.;.;.;.;
MVP
0.98
ClinPred
0.87
D
GERP RS
4.2
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.75
gMVP
0.75

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs781630603; hg19: chr16-2138318; COSMIC: COSV51925769; COSMIC: COSV51925769; API