chr16-2062595-C-G

Variant names:

• chr16-2062595-C-G
• rs769147552
• NM_000548.5:c.1356C>G

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_001406698.1(TSC2):​c.-165C>G variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,606,892 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 (★★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: TSC2 NM_001406698.1 5_prime_UTR_premature_start_codon_gain
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 3.20

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 Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.755

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.1356C>G	p.Phe452Leu	missense_variant	Exon 13 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.1356C>G	p.Phe452Leu	missense_variant	Exon 13 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152242 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 6.87e-7 AC: 1 AN: 1454650 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 722814

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.02e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152242 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74374

Gnomad4 AFR AF: 0.00

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: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Tuberous sclerosis syndrome Uncertain:1

Oct 06, 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 phenylalanine with leucine at codon 452 of the TSC2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with tuberous sclerosis complex 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

Jul 07, 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 are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with TSC2-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces phenylalanine with leucine at codon 452 of the TSC2 protein (p.Phe452Leu). The phenylalanine residue is highly conserved and there is a small physicochemical difference between phenylalanine and leucine. -

Hereditary cancer-predisposing syndrome Uncertain:1

Apr 30, 2020

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.F452L variant (also known as c.1356C>G), located in coding exon 12 of the TSC2 gene, results from a C to G substitution at nucleotide position 1356. The phenylalanine at codon 452 is replaced by leucine, an amino acid with highly similar properties. This amino acid position is well conserved in available vertebrate species. 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	0.99
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.30
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.86	D;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Uncertain	0.47
Eigen_PC	Uncertain	0.45
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.94	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.28	D
MetaRNN	Pathogenic	0.76	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.32	D
MutationAssessor	Uncertain	2.4	M;.;.;.;M;M;.;.;.;M;.;M;.;.;.
PrimateAI	Uncertain	0.69	T
PROVEAN	Pathogenic	-4.5	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
REVEL	Pathogenic	0.78
Sift	Uncertain	0.010	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Sift4G	Uncertain	0.041	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Polyphen		0.99	D;.;.;.;P;P;.;.;D;P;.;.;.;.;.
Vest4		0.83
MutPred		0.62		Gain of MoRF binding (P = 0.1078);Gain of MoRF binding (P = 0.1078);Gain of MoRF binding (P = 0.1078);.;Gain of MoRF binding (P = 0.1078);Gain of MoRF binding (P = 0.1078);Gain of MoRF binding (P = 0.1078);Gain of MoRF binding (P = 0.1078);.;Gain of MoRF binding (P = 0.1078);Gain of MoRF binding (P = 0.1078);Gain of MoRF binding (P = 0.1078);Gain of MoRF binding (P = 0.1078);Gain of MoRF binding (P = 0.1078);.;
MVP		0.97
ClinPred		0.99	D
GERP RS		4.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.50
gMVP		0.76

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: rs769147552; hg19: chr16-2112596;