9-132901666-C-T

Variant names:

• chr9-132901666-C-T
• NM_000368.5:c.2425G>A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4 BS2_Supporting

The NM_000368.5(TSC1):​c.2425G>A​(p.Glu809Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,828 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. E809Q) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: TSC1 NM_000368.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 7.25

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.39843485).
• BS2: High AC in GnomAdExome4 at 5 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC1	NM_000368.5	c.2425G>A	p.Glu809Lys	missense_variant	Exon 19 of 23	ENST00000298552.9	NP_000359.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC1	ENST00000298552.9	c.2425G>A	p.Glu809Lys	missense_variant	Exon 19 of 23	1	NM_000368.5	ENSP00000298552.3
TSC1	ENST00000490179.4	c.2425G>A	p.Glu809Lys	missense_variant	Exon 20 of 24	3		ENSP00000495533.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461828 Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5 AN XY: 727224

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Jul 13, 2024

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 indicates that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Tuberous sclerosis 1 Uncertain:1

Nov 07, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 809 of the TSC1 protein (p.Glu809Lys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TSC1-related conditions. ClinVar contains an entry for this variant (Variation ID: 1422802). 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. 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. -

Hereditary cancer-predisposing syndrome Uncertain:1

Jan 17, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.E809K variant (also known as c.2425G>A), located in coding exon 17 of the TSC1 gene, results from a G to A substitution at nucleotide position 2425. The glutamic acid at codon 809 is replaced by lysine, 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	0.17
BayesDel_addAF	Uncertain	0.090	D
BayesDel_noAF	Benign	-0.11
CADD	Benign	23
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.46	T;.;T;.;.;T;.;T;.;.;.
Eigen	Benign	-0.12
Eigen_PC	Benign	0.11
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.92	.;D;D;D;D;.;.;.;D;D;.
M_CAP	Benign	0.073	D
MetaRNN	Benign	0.40	T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.60	T
MutationAssessor	Benign	1.4	L;.;L;.;.;L;.;L;.;.;.
PrimateAI	Uncertain	0.55	T
PROVEAN	Benign	-1.8	N;N;N;.;.;.;.;.;.;.;.
REVEL	Uncertain	0.34
Sift	Benign	0.13	T;T;T;.;.;.;.;.;.;.;.
Sift4G	Benign	0.21	T;T;T;.;.;.;.;.;.;.;.
Polyphen		0.12	B;.;B;.;.;B;.;B;.;.;.
Vest4		0.55
MutPred		0.27		Gain of MoRF binding (P = 0.0025);.;Gain of MoRF binding (P = 0.0025);.;.;Gain of MoRF binding (P = 0.0025);.;Gain of MoRF binding (P = 0.0025);.;.;.;
MVP		0.63
MPC		0.58
ClinPred		0.89	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.27
gMVP		0.12

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr9-135777053; COSMIC: COSV53765908;