9-132902693-C-T

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_ModerateBS2

The NM_000368.5(TSC1):​c.2303G>A​(p.Arg768His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000328 in 1,614,068 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign 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. R768C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000034 ( 0 hom. )

Consequence

TSC1
NM_000368.5 missense

Scores

2
17

Clinical Significance

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

Conservation

PhyloP100: 2.86

Publications

2 publications found
Variant links:
Genes affected
TSC1 (HGNC:12362): (TSC complex subunit 1) This gene is a tumor suppressor gene that encodes the growth inhibitory protein hamartin. The encoded protein interacts with and stabilizes the GTPase activating protein tuberin. This hamartin-tuberin complex negatively regulates mammalian target of rapamycin complex 1 (mTORC1) signaling which is a major regulator of anabolic cell growth. This protein also functions as a co-chaperone for Hsp90 that inhibits its ATPase activity. This protein functions as a facilitator of Hsp90-mediated folding of kinase and non-kinase clients, including TSC2 and thereby preventing their ubiquitination and proteasomal degradation. Mutations in this gene have been associated with tuberous sclerosis and lymphangioleiomyomatosis. [provided by RefSeq, May 2022]
TSC1 Gene-Disease associations (from GenCC):
  • tuberous sclerosis
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • tuberous sclerosis 1
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, PanelApp Australia, Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae)
  • lung 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: Likely_benign. The variant received -6 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.114337206).
BS2
High AC in GnomAdExome4 at 50 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TSC1NM_000368.5 linkc.2303G>A p.Arg768His missense_variant Exon 18 of 23 ENST00000298552.9 NP_000359.1 Q92574-1Q86WV8X5D9D2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TSC1ENST00000298552.9 linkc.2303G>A p.Arg768His missense_variant Exon 18 of 23 1 NM_000368.5 ENSP00000298552.3 Q92574-1
TSC1ENST00000490179.4 linkc.2303G>A p.Arg768His missense_variant Exon 19 of 24 3 ENSP00000495533.2 A0A2R8Y6S8

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152202
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000795
AC:
2
AN:
251450
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000342
AC:
50
AN:
1461866
Hom.:
0
Cov.:
31
AF XY:
0.0000303
AC XY:
22
AN XY:
727234
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5750
European-Non Finnish (NFE)
AF:
0.0000432
AC:
48
AN:
1112012
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.487
Heterozygous variant carriers
0
3
6
9
12
15
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152202
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74360
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41438
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68042
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000293
Hom.:
0
Bravo
AF:
0.0000113
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

ClinVar

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

Submissions by phenotype

Tuberous sclerosis 1 Uncertain:1Benign:1
Oct 15, 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

- -

Tuberous sclerosis syndrome Uncertain:1
Aug 13, 2024
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 histidine at codon 768 of the TSC1 protein. Computational prediction suggests that this variant may not impact protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with TSC1-related disorders in the literature. This variant has been identified in 2/251450 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. -

Lymphangiomyomatosis;C1846385:Isolated focal cortical dysplasia type II;C1854465:Tuberous sclerosis 1 Uncertain:1
Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hereditary cancer-predisposing syndrome Uncertain:1
Jul 11, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R768H variant (also known as c.2303G>A), located in coding exon 16 of the TSC1 gene, results from a G to A substitution at nucleotide position 2303. The arginine at codon 768 is replaced by histidine, an amino acid with highly similar properties. This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.062
BayesDel_addAF
Benign
-0.078
T
BayesDel_noAF
Benign
-0.25
CADD
Benign
21
DANN
Uncertain
0.98
DEOGEN2
Benign
0.32
T;.;T;.;.;T;.;T;.;.;.
Eigen
Benign
-0.14
Eigen_PC
Benign
0.094
FATHMM_MKL
Uncertain
0.84
D
LIST_S2
Benign
0.85
.;D;D;T;D;.;.;.;D;D;.
M_CAP
Benign
0.022
T
MetaRNN
Benign
0.11
T;T;T;T;T;T;T;T;T;T;T
MetaSVM
Benign
-0.65
T
MutationAssessor
Benign
0.60
N;.;N;.;.;N;.;N;.;.;.
PhyloP100
2.9
PrimateAI
Benign
0.29
T
PROVEAN
Benign
-0.30
N;N;N;.;.;.;.;.;.;.;.
REVEL
Benign
0.28
Sift
Benign
0.17
T;T;T;.;.;.;.;.;.;.;.
Sift4G
Benign
0.094
T;T;T;.;.;.;.;.;.;.;.
Polyphen
0.056
B;.;B;.;.;B;.;B;.;.;.
Vest4
0.30
MutPred
0.26
Loss of MoRF binding (P = 0.0531);.;Loss of MoRF binding (P = 0.0531);.;.;Loss of MoRF binding (P = 0.0531);.;Loss of MoRF binding (P = 0.0531);.;.;.;
MVP
0.50
MPC
0.62
ClinPred
0.46
T
GERP RS
5.7
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.22
gMVP
0.25
Mutation Taster
=52/48
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: rs1033725987; hg19: chr9-135778080; COSMIC: COSV53772119; COSMIC: COSV53772119; API