16-2050414-A-C

Position:

• chr16-2050414-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001406680.1(TSC2):​c.-664A>C variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,664 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 Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TSC2 NM_001406680.1 5_prime_UTR_premature_start_codon_gain
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.262

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.22359344).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TSC2	NM_000548.5	c.153A>C	p.Glu51Asp	missense_variant	3/42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.153A>C	p.Glu51Asp	missense_variant	3/42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461664 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727124

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 30

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Tuberous sclerosis syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Nov 30, 2023

- -

Tuberous sclerosis 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 27, 2022

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt TSC2 protein function. ClinVar contains an entry for this variant (Variation ID: 577058). This variant has not been reported in the literature in individuals affected with TSC2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glutamic acid, which is acidic and polar, with aspartic acid, which is acidic and polar, at codon 51 of the TSC2 protein (p.Glu51Asp). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Uncertain	0.058	T
BayesDel_noAF	Benign	-0.15
CADD	Benign	22
DANN	Benign	0.64
DEOGEN2	Uncertain	0.52	D;.;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Benign	-0.30
Eigen_PC	Benign	-0.31
FATHMM_MKL	Benign	0.68	D
LIST_S2	Uncertain	0.92	D;D;D;T;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.30	D
MetaRNN	Benign	0.22	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.073	T
MutationAssessor	Benign	1.3	L;.;.;.;L;L;.;.;L;L;.;.;L;.;.;.
PrimateAI	Uncertain	0.54	T
PROVEAN	Benign	-1.1	N;.;.;N;.;N;.;.;N;N;.;.;.;.;.;N
REVEL	Benign	0.22
Sift	Benign	0.41	T;.;.;T;.;T;.;.;T;T;.;.;.;.;.;T
Sift4G	Benign	0.63	T;.;.;T;.;T;.;.;T;T;.;.;.;.;.;T
Polyphen		0.99	D;.;.;.;.;D;.;.;B;B;.;.;.;.;.;.
Vest4		0.40
MutPred		0.39		Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);.;Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);.;
MVP		0.85
ClinPred		0.39	T
GERP RS		1.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.071
gMVP		0.14

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: rs746366461; hg19: chr16-2100415;