16-2054301-G-C

Position:

• chr16-2054301-G-C

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP6

The NM_000548.5(TSC2):​c.342G>C​(p.Glu114Asp) 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. 16/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E114K) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: -1.09

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_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.048148245).
• BP6: Variant 16-2054301-G-C is Benign according to our data. Variant chr16-2054301-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 468014.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Likely_benign=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TSC2	NM_000548.5	c.342G>C	p.Glu114Asp	missense_variant	5/42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.342G>C	p.Glu114Asp	missense_variant	5/42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Tuberous sclerosis 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 04, 2024

This sequence change replaces glutamic acid, which is acidic and polar, with aspartic acid, which is acidic and polar, at codon 114 of the TSC2 protein (p.Glu114Asp). 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: 468014). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) 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. -

Hereditary cancer-predisposing syndrome Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 22, 2022

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.071
BayesDel_addAF	Benign	-0.094	T
BayesDel_noAF	Benign	-0.37
CADD	Benign	0.090
DANN	Benign	0.41
DEOGEN2	Benign	0.32	T;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Benign	-1.2
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.10	N
LIST_S2	Benign	0.74	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
M_CAP	Benign	0.011	T
MetaRNN	Benign	0.048	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.3	L;.;.;.;L;L;.;.;.;L;.;L;.;.;.
PrimateAI	Benign	0.45	T
PROVEAN	Benign	0.44	N;.;.;N;.;N;.;.;N;N;.;.;.;.;N
REVEL	Benign	0.20
Sift	Benign	0.80	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Sift4G	Benign	0.31	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Polyphen		0.0	B;.;.;.;.;B;.;.;B;B;.;.;.;.;.
Vest4		0.23
MutPred		0.36		Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);.;Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);.;Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);.;
MVP		0.67
ClinPred		0.026	T
GERP RS		-4.2
Varity_R		0.024
gMVP		0.18

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: rs1555497542; hg19: chr16-2104302;