9-132897193-G-A

Variant names:

• chr9-132897193-G-A
• rs1554813219
• NM_000368.5:c.2966C>T

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_000368.5(TSC1):​c.2966C>T​(p.Ala989Val) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign 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. A989S) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: TSC1 NM_000368.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 5.91
• Publications: 0 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.33439982).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC1	NM_000368.5	c.2966C>T	p.Ala989Val	missense_variant	Exon 22 of 23	ENST00000298552.9	NP_000359.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC1	ENST00000298552.9	c.2966C>T	p.Ala989Val	missense_variant	Exon 22 of 23	1	NM_000368.5	ENSP00000298552.3
TSC1	ENST00000490179.4	c.2966C>T	p.Ala989Val	missense_variant	Exon 23 of 24	3		ENSP00000495533.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Dec 29, 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; This variant is associated with the following publications: (PMID: 18466115) -

Tuberous sclerosis 1 Uncertain:1

Jan 31, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine with valine at codon 989 of the TSC1 protein (p.Ala989Val). The alanine residue is moderately conserved and there is a small physicochemical difference between alanine and valine. In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a TSC1-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Uncertain	0.10	D
BayesDel_noAF	Benign	-0.090
CADD	Uncertain	24
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.38	T;.;T;.;.;T;.;T;.;.;.
Eigen	Uncertain	0.59
Eigen_PC	Uncertain	0.56
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Benign	0.84	.;T;T;T;T;.;.;.;T;T;.
M_CAP	Benign	0.058	D
MetaRNN	Benign	0.33	T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.23	D
MutationAssessor	Uncertain	2.3	M;.;M;.;.;M;.;M;.;.;.
PhyloP100		5.9
PrimateAI	Uncertain	0.53	T
PROVEAN	Benign	-0.27	N;N;N;.;.;.;.;.;.;.;.
REVEL	Uncertain	0.39
Sift	Pathogenic	0.0	D;D;D;.;.;.;.;.;.;.;.
Sift4G	Uncertain	0.040	D;D;D;.;.;.;.;.;.;.;.
Polyphen		1.0	D;.;D;.;.;D;.;D;.;.;.
Vest4		0.52
MutPred		0.34		Loss of helix (P = 0.4835);.;Loss of helix (P = 0.4835);.;.;Loss of helix (P = 0.4835);.;Loss of helix (P = 0.4835);.;.;.;
MVP		0.59
MPC		0.55
ClinPred		0.89	D
GERP RS		4.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.53
gMVP		0.41
Mutation Taster		=65/35	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1554813219; hg19: chr9-135772580;