dbSNP rs1554814652: TSC1:p.Ala817Ser (chr9-132901642-C-A) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_000368.5(TSC1):c.2449G>T(p.Ala817Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,828 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

TSC1
NM_000368.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 7.59

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC1	NM_000368.5 link	c.2449G>T	p.Ala817Ser	missense_variant	Exon 19 of 23	ENST00000298552.9	NP_000359.1	Q92574-1Q86WV8X5D9D2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC1	ENST00000298552.9 link	c.2449G>T	p.Ala817Ser	missense_variant	Exon 19 of 23	1	NM_000368.5	ENSP00000298552.3		Q92574-1
TSC1	ENST00000490179.4 link	c.2449G>T	p.Ala817Ser	missense_variant	Exon 20 of 24	3		ENSP00000495533.2		A0A2R8Y6S8

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1461828

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727224

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:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000180

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Lymphangiomyomatosis;C1846385:Isolated focal cortical dysplasia type II;C1854465:Tuberous sclerosis 1

Uncertain:1

May 10, 2022

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Uncertain:1

Mar 15, 2022

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Isolated focal cortical dysplasia type II

Uncertain:1

Nov 02, 2023

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Tuberous sclerosis 1

Uncertain:1

Jan 28, 2023

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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt TSC1 protein function. ClinVar contains an entry for this variant (Variation ID: 534415). This variant has not been reported in the literature in individuals affected with TSC1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces alanine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 817 of the TSC1 protein (p.Ala817Ser). -

Hereditary cancer-predisposing syndrome

Uncertain:1

Nov 01, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.A817S variant (also known as c.2449G>T), located in coding exon 17 of the TSC1 gene, results from a G to T substitution at nucleotide position 2449. The alanine at codon 817 is replaced by serine, an amino acid with similar properties. This amino acid position is conserved. 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

Benign

0.14

BayesDel_addAF

Pathogenic

0.20

BayesDel_noAF

Uncertain

0.040

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.44

T;.;T;.;.;T;.;T;.;.;.

Eigen

Uncertain

0.61

Eigen_PC

Uncertain

0.64

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.87

.;D;D;D;D;.;.;.;D;D;.

M_CAP

Uncertain

0.15

MetaRNN

Uncertain

0.53

D;D;D;D;D;D;D;D;D;D;D

MetaSVM

Uncertain

0.044

MutationAssessor

Uncertain

2.0

M;.;M;.;.;M;.;M;.;.;.

PrimateAI

Uncertain

0.56

PROVEAN

Benign

-1.4

N;N;N;.;.;.;.;.;.;.;.

REVEL

Uncertain

0.47

Sift

Benign

0.083

T;T;T;.;.;.;.;.;.;.;.

Sift4G

Benign

0.089

T;T;T;.;.;.;.;.;.;.;.

Polyphen

1.0

D;.;D;.;.;D;.;D;.;.;.

Vest4

0.81

MutPred

0.30

Gain of disorder (P = 0.0508);.;Gain of disorder (P = 0.0508);.;.;Gain of disorder (P = 0.0508);.;Gain of disorder (P = 0.0508);.;.;.;

MVP

0.64

MPC

1.0

ClinPred

0.96

GERP RS

5.2

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

2.8

Varity_R

0.38

gMVP

0.17

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over