rs549612492

chr16-2074365-G-Achr16-2074365-G-C

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM1 BP4_Moderate BP6

The NM_000548.5(TSC2):c.2521G>A(p.Val841Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000062 in 1,611,728 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/20 in silico tools predict 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. V841L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., 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:4 B:3
• Conservation: PhyloP100: 0.815

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 Likely_benign. Variant got -1 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 16 uncertain in NM_000548.5
• BP4: Computational evidence support a benign effect (MetaRNN=0.06870705).
• BP6: Variant 16-2074365-G-A is Benign according to our data. Variant chr16-2074365-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 237994.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=3, Benign=1}. Variant chr16-2074365-G-A is described in Lovd as [Likely_benign]. Variant chr16-2074365-G-A is described in Lovd as [Benign].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TSC2	NM_000548.5	c.2521G>A	p.Val841Ile	missense_variant	22/42	ENST00000219476.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TSC2	ENST00000219476.9	c.2521G>A	p.Val841Ile	missense_variant	22/42	5	NM_000548.5

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152244 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: 0.00000617 AC: 9 AN: 1459484 Hom.: 0 Cov.: 31 AF XY: 0.00000964 AC XY: 7 AN XY: 726122

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000629

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152244 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74390

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

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Tuberous sclerosis 2 Uncertain:1 Benign:2

Uncertain significance, criteria provided, single submitter	clinical testing	Institute of Human Genetics, University of Leipzig Medical Center	Dec 20, 2019	- -
Likely benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -
Benign, criteria provided, single submitter	clinical testing	Invitae	Nov 24, 2023	- -

Tuberous sclerosis syndrome Uncertain:2

Uncertain significance, no assertion criteria provided	research	CSER _CC_NCGL, University of Washington	Aug 01, 2016	Found in patient having exome sequencing for an unrelated indication. No known history of Tuberous sclerosis complex. -
Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 13, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

TSC2-related disorder Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Mar 06, 2023

The TSC2 c.2521G>A variant is predicted to result in the amino acid substitution p.Val841Ile. 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. In ClinVar, this variant has conflicting interpretations of benign, likely benign, and uncertain significance (https://www.ncbi.nlm.nih.gov/clinvar/variation/237994/). 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 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 15, 2017

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.059
BayesDel_addAF	Benign	-0.0070	T
BayesDel_noAF	Benign	-0.25
Cadd	Benign	1.1
Dann	Benign	0.90
DEOGEN2	Uncertain	0.43	T;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.13	N
LIST_S2	Benign	0.84	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
M_CAP	Benign	0.029	D
MetaRNN	Benign	0.069	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.79	T
MutationAssessor	Benign	-0.95	N;.;.;.;N;N;.;.;.;N;.;N;.;.;.
MutationTaster	Benign	1.0	N;N;N;N;N;N;N
PrimateAI	Benign	0.28	T
PROVEAN	Benign	0.11	N;.;.;N;.;N;.;.;N;N;.;.;.;.;N
REVEL	Uncertain	0.32
Sift	Benign	1.0	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Sift4G	Benign	1.0	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Polyphen		0.0010	B;.;.;.;B;B;.;.;B;B;.;.;.;.;.
Vest4		0.33
MutPred		0.49		Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);.;Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);.;Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);.;
MVP		0.76
ClinPred		0.048	T
GERP RS		-2.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.018
gMVP		0.12

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: rs549612492; hg19: chr16-2124366; COSMIC: COSV104587133; COSMIC: COSV104587133;