rs587781782

Variant names:

• chr16-2079595-C-T
• rs587781782
• NM_000548.5:c.3323C>T

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP6

The NM_000548.5(TSC2):​c.3323C>T​(p.Ala1108Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000206 in 1,459,308 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. A1108A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:3
• Conservation: PhyloP100: 5.52
• 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: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP6: Variant 16-2079595-C-T is Benign according to our data. Variant chr16-2079595-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 141482.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.3323C>T	p.Ala1108Val	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.3323C>T	p.Ala1108Val	missense_variant	Exon 29 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000410 AC: 1 AN: 244108 AF XY: 0.00000752

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000549

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1459308 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 725862

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

American (AMR) AF: 0.00 AC: 0 AN: 44582

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26090

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39644

South Asian (SAS) AF: 0.00 AC: 0 AN: 86054

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51952

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

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111512

Other (OTH) AF: 0.0000166 AC: 1 AN: 60250

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:3

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

- -

Jun 02, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Tuberous sclerosis syndrome Uncertain:1

Jul 19, 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 alanine with valine at codon 1108 of the TSC2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 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 TSC2-related disorders in the literature. This variant has been identified in 1/244108 chromosomes 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. -

Hereditary cancer-predisposing syndrome Uncertain:1

Apr 16, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.A1108V variant (also known as c.3323C>T), located in coding exon 28 of the TSC2 gene, results from a C to T substitution at nucleotide position 3323. The alanine at codon 1108 is replaced by valine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

not provided Benign:1

May 03, 2019

GeneDx

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	0.27
BayesDel_addAF	Uncertain	0.12	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	28
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.58	D;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Uncertain	0.55
Eigen_PC	Uncertain	0.53
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	Pathogenic	0.54	D
MetaRNN	Uncertain	0.61	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.42	D
MutationAssessor	Benign	1.6	L;.;.;.;.;.;.;.;.;L;.;.;.;.;.
PhyloP100		5.5
PrimateAI	Uncertain	0.69	T
PROVEAN	Benign	-2.0	N;.;.;N;.;N;.;.;N;N;.;.;.;.;N
REVEL	Uncertain	0.50
Sift	Uncertain	0.023	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Sift4G	Benign	0.12	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Polyphen		1.0	D;.;.;.;D;D;.;.;D;D;.;.;.;.;.
Vest4		0.55
MVP		0.84
ClinPred		0.80	D
GERP RS		4.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.076
gMVP		0.50
Mutation Taster		=58/42	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		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: rs587781782; hg19: chr16-2129596;