16-2079598-C-T

Variant names:

• chr16-2079598-C-T
• rs796053474
• NM_000548.5:c.3326C>T

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 1P and 5B. PP3 BP6 BS2

The NM_000548.5(TSC2):​c.3326C>T​(p.Pro1109Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000617 in 1,459,200 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P1109A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:4
• Conservation: PhyloP100: 7.22
• Publications: 2 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 -4 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.82
• BP6: Variant 16-2079598-C-T is Benign according to our data. Variant chr16-2079598-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 207676.
• BS2: High AC in GnomAdExome4 at 9 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.3326C>T	p.Pro1109Leu	missense_variant	Exon 29 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.3326C>T	p.Pro1109Leu	missense_variant	Exon 29 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00 AC: 0 AN: 244002 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000617 AC: 9 AN: 1459200 Hom.: 0 Cov.: 32 AF XY: 0.00000827 AC XY: 6 AN XY: 725772

African (AFR) AF: 0.00 AC: 0 AN: 33472

American (AMR) AF: 0.0000673 AC: 3 AN: 44576

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26092

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39638

South Asian (SAS) AF: 0.00 AC: 0 AN: 86038

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51926

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5746

European-Non Finnish (NFE) AF: 0.00000450 AC: 5 AN: 1111482

Other (OTH) AF: 0.00 AC: 0 AN: 60230

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000905 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:4

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Tuberous sclerosis 2 Benign:2

Nov 07, 2021

Genome-Nilou Lab

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 06, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Uncertain:1

May 28, 2024

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome Uncertain:1

Feb 24, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.P1109L variant (also known as c.3326C>T), located in coding exon 28 of the TSC2 gene, results from a C to T substitution at nucleotide position 3326. The proline at codon 1109 is replaced by leucine, an amino acid with similar properties. This amino acid position is highly 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. -

not specified Benign:1

Mar 12, 2014

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Lymphangiomyomatosis;C1846385:Isolated focal cortical dysplasia type II;C1860707:Tuberous sclerosis 2 Benign:1

Feb 14, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.33
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.27
CADD	Pathogenic	28
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.84	D;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Uncertain	0.61
Eigen_PC	Uncertain	0.54
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.59	D
MetaRNN	Pathogenic	0.82	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.73	D
MutationAssessor	Uncertain	2.3	M;.;.;.;.;.;.;.;.;M;.;.;.;.;.
PhyloP100		7.2
PrimateAI	Uncertain	0.78	T
PROVEAN	Pathogenic	-4.5	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
REVEL	Uncertain	0.61
Sift	Uncertain	0.021	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Sift4G	Uncertain	0.031	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Polyphen		1.0	D;.;.;.;D;D;.;.;D;D;.;.;.;.;.
Vest4		0.72
MutPred		0.26		Loss of loop (P = 0.0073);.;Loss of loop (P = 0.0073);.;.;.;.;Loss of loop (P = 0.0073);.;Loss of loop (P = 0.0073);.;.;.;.;.;
MVP		0.87
ClinPred		1.0	D
GERP RS		4.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.25
gMVP		0.51
Mutation Taster		=0/100	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs796053474; hg19: chr16-2129599; COSMIC: COSV54763957; COSMIC: COSV54763957;