16-2084534-C-T

Position:

chr16-2084534-C-T

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM5BP4BS2

The NM_000548.5(TSC2):c.4312C>T(p.Arg1438Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000087 in 1,609,090 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. R1438Q) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 34)

Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

TSC2
NM_000548.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:1

Conservation

PhyloP100: 0.466

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -3 ACMG points.

PM5

Other missense variant is known to change same aminoacid residue: Variant chr16-2084535-G-A is described in Lovd as [Pathogenic].

BP4

Computational evidence support a benign effect (MetaRNN=0.30031157).

BS2

High AC in GnomAdExome4 at 12 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TSC2	NM_000548.5 linkuse as main transcript	c.4312C>T	p.Arg1438Trp	missense_variant	34/42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9 linkuse as main transcript	c.4312C>T	p.Arg1438Trp	missense_variant	34/42	5	NM_000548.5	ENSP00000219476		P49815-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152240

Hom.:

Cov.:

show subpopulations

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:

0.000414

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000420

AC:

AN:

238204

Hom.:

AF XY:

0.00000765

AC XY:

AN XY:

130652

show subpopulations

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 SAS exome

AF:

0.0000332

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000824

AC:

AN:

1456850

Hom.:

Cov.:

AF XY:

0.00000828

AC XY:

AN XY:

724788

show subpopulations

Gnomad4 AFR exome

AF:

0.0000598

Gnomad4 AMR exome

AF:

0.0000225

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000582

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000180

Gnomad4 OTH exome

AF:

0.0000332

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152240

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74370

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000414

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

ExAC

AF:

0.00000830

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Tuberous sclerosis 2

Uncertain:1Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -
Benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 15, 2023	- -

Tuberous sclerosis syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Jan 11, 2024

- -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 15, 2014

p.Arg1438Trp (CGG>TGG): c.4312 C>T in exon 34 of the TSC2 gene (NM_000548.3) A variant of unknown significance has been identified in the TSC2 gene. The R1438W variant has not been published as a mutation, nor has it been reported as a benign polymorphism to our knowledge. A different amino acid substitution at the same position (R1438Q) was reported as a de novo mutation in an individual with tuberous sclerosis (Roberts et al., 2004). R1438W was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The R1438W variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. In silico analysis predicts this variant is probably damaging to the protein structure/function. However, the R1438W variant alters a poorly conserved position in the protein. Additionally, it is not within any known functional domain of the tuberin protein, where many pathogenic missense mutations have been identified (Northrup et al., 2011; Au et al., 2007). Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic mutation or a rare benign variant. The variant is found in EPILEPSY panel(s). -

Isolated focal cortical dysplasia type II

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Mar 24, 2024

- -

Hereditary cancer-predisposing syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 09, 2022

The p.R1438W variant (also known as c.4312C>T), located in coding exon 33 of the TSC2 gene, results from a C to T substitution at nucleotide position 4312. The arginine at codon 1438 is replaced by tryptophan, an amino acid with dissimilar properties. This amino acid position is poorly 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.073

BayesDel_addAF

Uncertain

0.13

BayesDel_noAF

Uncertain

0.040

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.67

D;.;.;.;.;.;.;.;.;.;.;.;T;.;T

Eigen

Benign

-0.056

Eigen_PC

Benign

-0.14

FATHMM_MKL

Benign

0.44

LIST_S2

Uncertain

0.96

D;D;D;D;D;D;D;D;D;D;D;D;D;D;D

M_CAP

Pathogenic

0.62

MetaRNN

Benign

0.30

T;T;T;T;T;T;T;T;T;T;T;T;T;T;T

MetaSVM

Uncertain

0.37

MutationAssessor

Benign

1.7

L;.;.;.;.;.;.;.;.;.;.;.;.;.;.

MutationTaster

Benign

0.56

D;D;D;D;D;D;D

PrimateAI

Benign

0.44

PROVEAN

Uncertain

-2.9

D;.;.;D;.;D;.;.;D;D;.;.;.;.;D

REVEL

Uncertain

0.43

Sift

Uncertain

0.0010

D;.;.;D;.;D;.;.;D;D;.;.;.;.;D

Sift4G

Uncertain

0.014

D;.;.;D;.;D;.;.;D;D;.;.;.;.;D

Polyphen

0.99

D;.;.;.;D;D;.;.;D;D;.;.;.;.;.

Vest4

0.39

MutPred

0.30

Loss of solvent accessibility (P = 0.0036);.;.;.;.;.;.;Loss of solvent accessibility (P = 0.0036);.;.;.;.;.;.;.;

MVP

0.84

ClinPred

0.87

GERP RS

5.2

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.2

Varity_R

0.14

gMVP

0.38

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.040

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over