9-132921926-C-T

Variant summary

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

The NM_000368.5(TSC1):​c.556G>A​(p.Ala186Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,856 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. A186V) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

TSC1
NM_000368.5 missense

Scores

3
12
4

Clinical Significance

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

Conservation

PhyloP100: 3.86

Publications

6 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: Uncertain_significance. The variant received 4 ACMG points.

PM1
In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 15 uncertain in NM_000368.5
PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TSC1NM_000368.5 linkc.556G>A p.Ala186Thr missense_variant Exon 7 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.556G>A p.Ala186Thr missense_variant Exon 7 of 23 1 NM_000368.5 ENSP00000298552.3 Q92574-1
TSC1ENST00000490179.4 linkc.556G>A p.Ala186Thr missense_variant Exon 8 of 24 3 ENSP00000495533.2 A0A2R8Y6S8

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251380
AF XY:
0.00000736
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461856
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727232
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111984
Other (OTH)
AF:
0.00
AC:
0
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
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

Exome 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
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.00
Hom.:
0

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
Sep 27, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely 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
May 14, 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 alanine with threonine at codon 186 of the TSC1 protein. Computational prediction is inconclusive regarding the impact of this variant on 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 1/251380 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. -

Isolated focal cortical dysplasia type II Uncertain:1
Jul 13, 2023
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hereditary cancer-predisposing syndrome Uncertain:1
May 08, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.A186T variant (also known as c.556G>A), located in coding exon 5 of the TSC1 gene, results from a G to A substitution at nucleotide position 556. The alanine at codon 186 is replaced by threonine, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.30
BayesDel_addAF
Pathogenic
0.20
D
BayesDel_noAF
Pathogenic
0.14
CADD
Uncertain
25
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.49
T;.;T;.;T;.;T;.;.;.;.;.;.;.;.;.;.;T;.;.
Eigen
Uncertain
0.44
Eigen_PC
Uncertain
0.52
FATHMM_MKL
Uncertain
0.87
D
LIST_S2
Uncertain
0.95
.;D;D;D;.;.;.;D;D;.;D;.;.;D;D;D;D;D;D;D
M_CAP
Uncertain
0.096
D
MetaRNN
Uncertain
0.54
D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM
Uncertain
0.42
D
MutationAssessor
Uncertain
2.4
M;.;M;.;M;.;M;.;.;.;.;.;.;.;.;.;.;.;.;.
PhyloP100
3.9
PrimateAI
Uncertain
0.67
T
PROVEAN
Benign
-0.95
N;N;N;.;.;.;.;.;.;.;.;.;.;.;.;.;.;N;.;.
REVEL
Uncertain
0.53
Sift
Benign
0.097
T;D;T;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;.;.
Sift4G
Uncertain
0.029
D;D;D;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;.;.
Polyphen
0.39
B;.;B;.;B;.;B;.;.;.;.;P;P;P;.;.;.;P;.;.
Vest4
0.71
MutPred
0.67
Loss of helix (P = 0.0093);.;Loss of helix (P = 0.0093);Loss of helix (P = 0.0093);Loss of helix (P = 0.0093);Loss of helix (P = 0.0093);Loss of helix (P = 0.0093);Loss of helix (P = 0.0093);Loss of helix (P = 0.0093);.;.;Loss of helix (P = 0.0093);Loss of helix (P = 0.0093);Loss of helix (P = 0.0093);Loss of helix (P = 0.0093);Loss of helix (P = 0.0093);.;Loss of helix (P = 0.0093);.;Loss of helix (P = 0.0093);
MVP
0.82
MPC
1.1
ClinPred
0.79
D
GERP RS
6.1
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.091
gMVP
0.25
Mutation Taster
=73/27
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: rs1279777367; hg19: chr9-135797313; COSMIC: COSV53774638; COSMIC: COSV53774638; API