16-2053384-C-G

Variant names:

• chr16-2053384-C-G
• rs45517099
• NM_000548.5:c.268C>G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000548.5(TSC2):​c.268C>G​(p.Gln90Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. 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. Q90R) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.25
• Publications: 0 publications found

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]

TSC2 Gene-Disease associations (from GenCC):

• tuberous sclerosis

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• tuberous sclerosis 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, Ambry Genetics
• 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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.22930452).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.268C>G	p.Gln90Glu	missense_variant	Exon 4 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.268C>G	p.Gln90Glu	missense_variant	Exon 4 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Tuberous sclerosis syndrome Uncertain:1

Sep 17, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces glutamine with glutamic acid at codon 90 of the TSC2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with TSC2-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Tuberous sclerosis 2 Uncertain:1

Apr 11, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamine, which is neutral and polar, with glutamic acid, which is acidic and polar, at codon 90 of the TSC2 protein (p.Gln90Glu). 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. 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 with a negative predictive value of 95%. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.079
BayesDel_addAF	Uncertain	0.020	T
BayesDel_noAF	Benign	-0.21
CADD	Uncertain	24
DANN	Uncertain	0.98
DEOGEN2	Benign	0.37	T;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Benign	-0.13
Eigen_PC	Benign	-0.076
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.96	D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.094	D
MetaRNN	Benign	0.23	T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.22	T
MutationAssessor	Benign	1.4	L;.;.;.;L;L;.;.;L;.;L;.;.;.
PhyloP100		1.3
PrimateAI	Uncertain	0.54	T
PROVEAN	Benign	-0.64	N;.;.;N;.;N;.;.;N;.;.;.;.;N
REVEL	Uncertain	0.37
Sift	Benign	0.62	T;.;.;T;.;T;.;.;T;.;.;.;.;T
Sift4G	Benign	1.0	T;.;.;T;.;T;.;.;T;.;.;.;.;T
Polyphen		0.93	P;.;.;.;.;P;.;.;B;.;.;.;.;.
Vest4		0.57
MutPred		0.32		Gain of disorder (P = 0.0696);Gain of disorder (P = 0.0696);Gain of disorder (P = 0.0696);.;Gain of disorder (P = 0.0696);Gain of disorder (P = 0.0696);Gain of disorder (P = 0.0696);Gain of disorder (P = 0.0696);Gain of disorder (P = 0.0696);Gain of disorder (P = 0.0696);Gain of disorder (P = 0.0696);Gain of disorder (P = 0.0696);Gain of disorder (P = 0.0696);.;
MVP		0.80
ClinPred		0.25	T
GERP RS		4.8
PromoterAI		-0.015	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.083
gMVP		0.28
Mutation Taster		=87/13	polymorphism

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

Other links and lift over

dbSNP: rs45517099; hg19: chr16-2103385;