rs768189353

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_000368.5(TSC1):​c.2023G>T​(p.Asp675Tyr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,694 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D675E) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

TSC1
NM_000368.5 missense

Scores

8
10
1

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 7.91
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]

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.894

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TSC1NM_000368.5 linkc.2023G>T p.Asp675Tyr missense_variant Exon 16 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.2023G>T p.Asp675Tyr missense_variant Exon 16 of 23 1 NM_000368.5 ENSP00000298552.3 Q92574-1
TSC1ENST00000490179.4 linkc.2023G>T p.Asp675Tyr missense_variant Exon 17 of 24 3 ENSP00000495533.2 A0A2R8Y6S8

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
AF:
0.00000274
AC:
4
AN:
1461694
Hom.:
0
Cov.:
31
AF XY:
0.00000138
AC XY:
1
AN XY:
727146
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000232
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000180
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
33

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Tuberous sclerosis syndrome Uncertain:1
Jun 15, 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 aspartic acid with tyrosine at codon 675 of the TSC1 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 TSC1-related disorders in the literature. This variant has not been identified 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. -

Tuberous sclerosis 1 Uncertain:1
Sep 29, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces aspartic acid with tyrosine at codon 675 of the TSC1 protein (p.Asp675Tyr). The aspartic acid residue is highly conserved and there is a large physicochemical difference between aspartic acid and tyrosine. 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 are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 411283). This variant has not been reported in the literature in individuals affected with TSC1-related conditions. This variant is not present in population databases (ExAC no frequency). -

Hereditary cancer-predisposing syndrome Uncertain:1
Mar 12, 2022
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The p.D675Y variant (also known as c.2023G>T), located in coding exon 14 of the TSC1 gene, results from a G to T substitution at nucleotide position 2023. The aspartic acid at codon 675 is replaced by tyrosine, an amino acid with highly dissimilar properties. This amino acid position is conserved. 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 v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.81
BayesDel_addAF
Pathogenic
0.43
D
BayesDel_noAF
Pathogenic
0.39
CADD
Pathogenic
31
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.72
D;.;D;.;.;D;.;D;.;.;.
Eigen
Pathogenic
0.87
Eigen_PC
Pathogenic
0.85
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.95
.;D;D;D;D;.;.;.;D;D;.
M_CAP
Uncertain
0.20
D
MetaRNN
Pathogenic
0.89
D;D;D;D;D;D;D;D;D;D;D
MetaSVM
Uncertain
0.79
D
MutationAssessor
Uncertain
2.5
M;.;M;.;.;M;.;M;.;.;.
PrimateAI
Uncertain
0.76
T
PROVEAN
Uncertain
-3.7
D;D;D;.;.;.;.;.;.;.;.
REVEL
Pathogenic
0.88
Sift
Uncertain
0.0020
D;D;D;.;.;.;.;.;.;.;.
Sift4G
Uncertain
0.0080
D;D;D;.;.;.;.;.;.;.;.
Polyphen
1.0
D;.;D;.;.;D;.;D;.;.;.
Vest4
0.97
MutPred
0.74
Loss of disorder (P = 0.0152);.;Loss of disorder (P = 0.0152);.;.;Loss of disorder (P = 0.0152);.;Loss of disorder (P = 0.0152);.;Loss of disorder (P = 0.0152);.;
MVP
0.88
MPC
1.6
ClinPred
1.0
D
GERP RS
5.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.73
gMVP
0.65

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs768189353; hg19: chr9-135779816; API