chr16-2084472-G-A

Variant names:

• chr16-2084472-G-A
• rs1343536158
• NM_000548.5:c.4250G>A

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_Moderate BP6 BS2

The NM_000548.5(TSC2):​c.4250G>A​(p.Arg1417Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000687 in 1,456,644 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. R1417G) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0000069 (0 hom.)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1
• Conservation: PhyloP100: 1.76
• 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: Benign. The variant received -7 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.24343136).
• BP6: Variant 16-2084472-G-A is Benign according to our data. Variant chr16-2084472-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 468073.
• BS2: High AC in GnomAdExome4 at 10 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.4250G>A	p.Arg1417Gln	missense_variant	Exon 34 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.4250G>A	p.Arg1417Gln	missense_variant	Exon 34 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD2 exomes AF: 0.00 AC: 0 AN: 239060 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: 0.00000687 AC: 10 AN: 1456644 Hom.: 0 Cov.: 33 AF XY: 0.00000552 AC XY: 4 AN XY: 724432

African (AFR) AF: 0.00 AC: 0 AN: 33362

American (AMR) AF: 0.0000226 AC: 1 AN: 44268

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26026

East Asian (EAS) AF: 0.00 AC: 0 AN: 39438

South Asian (SAS) AF: 0.0000117 AC: 1 AN: 85678

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51440

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00000720 AC: 8 AN: 1110462

Other (OTH) AF: 0.00 AC: 0 AN: 60208

GnomAD4 genome Cov.: 34

Alfa AF: 0.0000631 Hom.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Tuberous sclerosis syndrome Uncertain:1

Jun 26, 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 arginine with glutamine at codon 1417 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 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. -

TSC2-related disorder Uncertain:1

Mar 29, 2024

PreventionGenetics, part of Exact Sciences

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

The TSC2 c.4250G>A variant is predicted to result in the amino acid substitution p.Arg1417Gln. To our knowledge, this variant has not been reported in the literature or in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Hereditary cancer-predisposing syndrome Uncertain:1

Jan 21, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R1417Q variant (also known as c.4250G>A), located in coding exon 33 of the TSC2 gene, results from a G to A substitution at nucleotide position 4250. The arginine at codon 1417 is replaced by glutamine, an amino acid with highly similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -

Tuberous sclerosis 2 Benign:1

Dec 26, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.076
BayesDel_addAF	Uncertain	0.16	D
BayesDel_noAF	Uncertain	-0.010
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Benign	0.33	T;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Benign	-0.32
Eigen_PC	Benign	-0.29
FATHMM_MKL	Benign	0.18	N
LIST_S2	Pathogenic	0.99	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.21	D
MetaRNN	Benign	0.24	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.61	T
MutationAssessor	Benign	1.6	L;.;.;.;.;.;.;.;.;.;.;.;.;.;.
PhyloP100		1.8
PrimateAI	Benign	0.47	T
PROVEAN	Benign	-0.46	N;.;.;N;.;N;.;.;N;N;.;.;.;.;N
REVEL	Uncertain	0.53
Sift	Benign	0.098	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Sift4G	Benign	0.47	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Polyphen		0.51	P;.;.;.;P;P;.;.;P;P;.;.;.;.;.
Vest4		0.39
MVP		0.93
ClinPred		0.21	T
GERP RS		2.7
Varity_R		0.048
gMVP		0.20
Mutation Taster		=100/0	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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: rs1343536158; hg19: chr16-2134473;