NM_000368.5:c.23G>A

Variant names:

• chr9-132928850-C-T
• NM_000368.5:c.23G>A

Variant summary

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

The NM_000368.5(TSC1):​c.23G>A​(p.Gly8Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,854 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: 6.8e-7 (0 hom.)
• Consequence: TSC1 NM_000368.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.99

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 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	c.23G>A	p.Gly8Glu	missense_variant	Exon 3 of 23	ENST00000298552.9	NP_000359.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC1	ENST00000298552.9	c.23G>A	p.Gly8Glu	missense_variant	Exon 3 of 23	1	NM_000368.5	ENSP00000298552.3
TSC1	ENST00000490179.4	c.23G>A	p.Gly8Glu	missense_variant	Exon 4 of 24	3		ENSP00000495533.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461854 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727234

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Tuberous sclerosis 1 Uncertain:1

Aug 08, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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: 1379978). 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: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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. This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 8 of the TSC1 protein (p.Gly8Glu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.27
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.040
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.45	T;.;T;.;T;.;T;.;.;.;.;.;.;.;.;.;.;T;.;.;.
Eigen	Uncertain	0.44
Eigen_PC	Uncertain	0.54
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.89	.;D;D;D;.;.;.;D;D;.;D;.;.;D;D;D;D;D;D;D;D
M_CAP	Benign	0.065	D
MetaRNN	Uncertain	0.72	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.13	D
MutationAssessor	Uncertain	2.5	M;M;M;.;M;.;M;.;.;M;.;.;.;.;.;.;.;.;.;.;.
PrimateAI	Uncertain	0.55	T
PROVEAN	Benign	-0.53	N;N;N;.;.;.;.;.;.;.;.;.;.;.;.;.;.;N;.;.;.
REVEL	Uncertain	0.42
Sift	Benign	0.16	T;T;T;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;.;.;.
Sift4G	Benign	0.13	T;T;T;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;.;.;.
Polyphen		0.11	B;.;B;.;B;.;B;.;.;.;.;D;D;D;.;.;.;D;.;.;.
Vest4		0.40
MutPred		0.59		Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);
MVP		0.59
MPC		1.5
ClinPred		0.79	D
GERP RS		6.2
Varity_R		0.15
gMVP		0.60

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: chr9-135804237; COSMIC: COSV53775555;