16-2079405-G-C

Position:

• chr16-2079405-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM2 PM5 BP4_Moderate

The NM_000548.5(TSC2):​c.3261G>C​(p.Glu1087Asp) 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. 13/20 in silico tools predict 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. E1087?) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1 O:1
• Conservation: PhyloP100: 0.0840

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr16-2079402-GGAG-GAA is described in Lovd as [Pathogenic].
• BP4: Computational evidence support a benign effect (MetaRNN=0.11942372).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TSC2	NM_000548.5	c.3261G>C	p.Glu1087Asp	missense_variant	28/42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.3261G>C	p.Glu1087Asp	missense_variant	28/42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Tuberous sclerosis 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 27, 2021

This variant has not been reported in the literature in individuals affected with TSC2-related conditions. This sequence change replaces glutamic acid, a(n) acidic and polar amino acid, with aspartic acid, a(n) acidic and polar amino acid, at codon 1087 of the TSC2 protein (p.Glu1087Asp). This variant is not present in population databases (gnomAD no frequency). ClinVar contains an entry for this variant (Variation ID: 49588). 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. -

Tuberous sclerosis syndrome Other:1

not provided, no classification provided

curation

Tuberous sclerosis database (TSC2)

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.061
BayesDel_addAF	Uncertain	0.060	T
BayesDel_noAF	Benign	-0.15
CADD	Benign	12
DANN	Benign	0.65
DEOGEN2	Benign	0.42	T;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Benign	-0.98
Eigen_PC	Benign	-0.92
FATHMM_MKL	Benign	0.72	D
LIST_S2	Benign	0.83	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
M_CAP	Benign	0.019	T
MetaRNN	Benign	0.12	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.78	T
MutationAssessor	Benign	1.3	L;.;.;.;.;.;.;.;.;L;.;.;.;.;.
PrimateAI	Uncertain	0.51	T
PROVEAN	Benign	-0.63	N;.;.;N;.;N;.;.;N;N;.;.;.;.;N
REVEL	Uncertain	0.63
Sift	Benign	0.57	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Sift4G	Benign	0.49	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Polyphen		0.0010	B;.;.;.;B;B;.;.;B;B;.;.;.;.;.
Vest4		0.40
MutPred		0.082		Loss of glycosylation at P1092 (P = 0.1955);.;Loss of glycosylation at P1092 (P = 0.1955);.;.;.;.;Loss of glycosylation at P1092 (P = 0.1955);.;Loss of glycosylation at P1092 (P = 0.1955);.;.;.;.;.;
MVP		0.94
ClinPred		0.044	T
GERP RS		-3.1
Varity_R		0.029
gMVP		0.42

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

LitVar

Other links and lift over

dbSNP: rs45438093; hg19: chr16-2129406;