rs45517418

chr16-2088504-A-Cchr16-2088504-A-Gchr16-2088504-A-T

Variant summary

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

The NM_000548.5(TSC2):c.5318A>C(p.His1773Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,558 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H1773R) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1 O:1
• Conservation: PhyloP100: 1.91

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 Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TSC2	NM_000548.5	c.5318A>C	p.His1773Pro	missense_variant	42/42	ENST00000219476.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TSC2	ENST00000219476.9	c.5318A>C	p.His1773Pro	missense_variant	42/42	5	NM_000548.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460558 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 726580

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.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Tuberous sclerosis 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jun 18, 2023

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. Experimental studies have shown that this missense change does not substantially affect TSC2 function (PMID: 22903760). 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: 49920). This missense change has been observed in individual(s) with tuberous sclerosis complex (PMID: 10732801). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces histidine, which is basic and polar, with proline, which is neutral and non-polar, at codon 1773 of the TSC2 protein (p.His1773Pro). -

Tuberous sclerosis syndrome Other:1

not provided, no classification provided

curation

Tuberous sclerosis database (TSC2)

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.060
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.12
Cadd	Benign	9.2
Dann	Benign	0.48
DEOGEN2	Uncertain	0.56	D;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Benign	-0.79
Eigen_PC	Benign	-0.73
FATHMM_MKL	Benign	0.53	D
LIST_S2	Benign	0.75	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
M_CAP	Uncertain	0.092	D
MetaRNN	Uncertain	0.62	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Benign	-0.64	T
MutationAssessor	Benign	0.71	N;.;.;.;.;.;.;.;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	N;N;N;N;N;N;N
PrimateAI	Benign	0.39	T
PROVEAN	Uncertain	-2.5	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
REVEL	Uncertain	0.50
Sift	Benign	0.097	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Sift4G	Benign	0.25	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Polyphen		0.0020	B;.;.;.;B;B;.;.;B;B;.;.;.;.;.
Vest4		0.39
MutPred		0.72		Gain of relative solvent accessibility (P = 0.005);.;.;.;.;.;.;.;.;.;.;.;.;.;.;
MVP		1.0
ClinPred		0.21	T
GERP RS		3.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.18
gMVP		0.38

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs45517418; hg19: chr16-2138505;