rs370324876

chr16-2070492-C-Gchr16-2070492-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PM5 PP3_Moderate

The NM_000548.5(TSC2):c.1753C>G(p.Arg585Gly) variant causes a missense change. The variant allele was found at a frequency of 0.0000197 in 152,234 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. R585C) has been classified as Likely benign.

• Frequency: Genomes: 𝑓 0.000020 (0 hom., cov: 33)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 4.81

Genes affected

TSC2 (HGNC:12363): (TSC complex subunit 2) This gene is a tumor suppressor gene that encodes the growth inhibitory protein tuberin. Tuberin interacts with hamartin to form the TSC protein complex which functions in the control of cell growth. This TSC protein complex negatively regulates mammalian target of rapamycin complex 1 (mTORC1) signaling which is a major regulator of anabolic cell growth. Mutations in this gene have been associated with tuberous sclerosis and lymphangioleiomyomatosis. [provided by RefSeq, May 2022]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr16-2070493-G-A is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.862

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TSC2	NM_000548.5	c.1753C>G	p.Arg585Gly	missense_variant	17/42	ENST00000219476.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TSC2	ENST00000219476.9	c.1753C>G	p.Arg585Gly	missense_variant	17/42	5	NM_000548.5

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152234 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000724

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 34

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152234 Hom.: 0 Cov.: 33 AF XY: 0.0000403 AC XY: 3 AN XY: 74372

Gnomad4 AFR AF: 0.0000724

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Tuberous sclerosis 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 22, 2023

This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 585 of the TSC2 protein (p.Arg585Gly). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TSC2-related conditions. ClinVar contains an entry for this variant (Variation ID: 855124). 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 TSC2 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. -

Lymphangiomyomatosis;C1846385:Isolated focal cortical dysplasia type II;C1860707:Tuberous sclerosis 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Jan 14, 2022

- -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 05, 2022

The p.R585G variant (also known as c.1753C>G), located in coding exon 16 of the TSC2 gene, results from a C to G substitution at nucleotide position 1753. The arginine at codon 585 is replaced by glycine, an amino acid with dissimilar properties. This amino acid position is conserved. In addition, this alteration is predicted to be deleterious by in silico analysis. 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	Pathogenic	0.58
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
Cadd	Benign	21
Dann	Uncertain	0.98
DEOGEN2	Pathogenic	0.90	D;.;.;.;.;.;.;.;.;.;.;.;D;.;D
Eigen	Benign	0.13
Eigen_PC	Benign	0.052
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;D
M_CAP	Uncertain	0.28	D
MetaRNN	Pathogenic	0.86	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.21	D
MutationAssessor	Uncertain	2.6	M;.;.;.;M;M;.;.;.;M;.;M;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
PrimateAI	Benign	0.48	T
PROVEAN	Pathogenic	-5.1	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
REVEL	Pathogenic	0.68
Sift	Uncertain	0.019	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Sift4G	Benign	0.14	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Polyphen		0.96	D;.;.;.;P;P;.;.;P;P;.;.;.;.;.
Vest4		0.90
MutPred		0.65		Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);.;Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);.;Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);Gain of loop (P = 0.0121);.;
MVP		0.96
ClinPred		0.97	D
GERP RS		4.0
Varity_R		0.74
gMVP		0.72

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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

Other links and lift over

dbSNP: rs370324876; hg19: chr16-2120493;