chr16-2083758-G-A

Variant names:

• chr16-2083758-G-A
• rs1555513513
• NM_000548.5:c.3947G>A

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP6

The NM_000548.5(TSC2):​c.3947G>A​(p.Gly1316Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000686 in 1,457,778 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 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. G1316A) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 1.65
• 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: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.05232954).
• BP6: Variant 16-2083758-G-A is Benign according to our data. Variant chr16-2083758-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1383306.We mark this variant Likely_benign, oryginal submission is: [Conflicting_classifications_of_pathogenicity].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.3947G>A	p.Gly1316Glu	missense_variant	Exon 33 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.3947G>A	p.Gly1316Glu	missense_variant	Exon 33 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome AF: 6.86e-7 AC: 1 AN: 1457778 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 724868

African (AFR) AF: 0.00 AC: 0 AN: 33470

American (AMR) AF: 0.00 AC: 0 AN: 44228

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26018

East Asian (EAS) AF: 0.00 AC: 0 AN: 39600

South Asian (SAS) AF: 0.00 AC: 0 AN: 85434

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51954

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5754

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111062

Other (OTH) AF: 0.00 AC: 0 AN: 60258

GnomAD4 genome Cov.: 34

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

Nov 04, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The glutamic acid amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with TSC2-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glycine with glutamic acid at codon 1316 of the TSC2 protein (p.Gly1316Glu). The glycine residue is weakly conserved and there is a moderate physicochemical difference between glycine and glutamic acid. -

Hereditary cancer-predisposing syndrome Benign:1

Nov 11, 2020

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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	0.058
BayesDel_addAF	Uncertain	0.016	T
BayesDel_noAF	Benign	-0.21
CADD	Benign	5.0
DANN	Benign	0.67
DEOGEN2	Benign	0.31	T;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Benign	-1.2
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.040	N
LIST_S2	Benign	0.75	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
M_CAP	Uncertain	0.21	D
MetaRNN	Benign	0.052	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.74	T
MutationAssessor	Benign	-1.9	N;.;.;.;.;.;.;.;.;.;.;.;.;.;.
PhyloP100		1.6
PrimateAI	Benign	0.38	T
PROVEAN	Benign	0.31	N;.;.;N;.;N;.;.;N;N;.;.;.;.;N
REVEL	Uncertain	0.45
Sift	Benign	1.0	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Sift4G	Benign	0.35	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Polyphen		0.0	B;.;.;.;B;B;.;.;B;B;.;.;.;.;.
Vest4		0.14
MutPred		0.14		Loss of catalytic residue at L1317 (P = 0.1289);.;.;.;.;.;.;Loss of catalytic residue at L1317 (P = 0.1289);.;.;.;.;.;.;.;
MVP		0.84
ClinPred		0.037	T
GERP RS		1.6
RBP_binding_hub_radar		0.92
RBP_regulation_power_radar		2.0
Varity_R		0.029
gMVP		0.17
Mutation Taster		=95/5	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: rs1555513513; hg19: chr16-2133759;