chr16-2079559-C-G

Position:

• chr16-2079559-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_000548.5(TSC2):​c.3287C>G​(p.Ser1096Cys) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.000000686 in 1,457,614 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: TSC2 NM_000548.5 missense, splice_region
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 5.42

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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.3570742).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TSC2	NM_000548.5	c.3287C>G	p.Ser1096Cys	missense_variant, splice_region_variant	29/42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.3287C>G	p.Ser1096Cys	missense_variant, splice_region_variant	29/42	5	NM_000548.5	ENSP00000219476

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000415 AC: 1 AN: 240976 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 131106

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000295

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS 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: 6.86e-7 AC: 1 AN: 1457614 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 724872

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000226

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Tuberous sclerosis 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 21, 2023

This sequence change replaces serine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 1096 of the TSC2 protein (p.Ser1096Cys). This variant is present in population databases (no rsID available, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with TSC2-related conditions. ClinVar contains an entry for this variant (Variation ID: 957650). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 18, 2021

The p.S1096C variant (also known as c.3287C>G), located in coding exon 28 of the TSC2 gene, results from a C to G substitution at nucleotide position 3287. The serine at codon 1096 is replaced by cysteine, an amino acid with dissimilar properties. This amino acid position is not well 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	0.075
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Uncertain	0.0
CADD	Benign	23
DANN	Benign	0.96
DEOGEN2	Uncertain	0.64	D;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Uncertain	0.32
Eigen_PC	Benign	0.21
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.92	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.18	D
MetaRNN	Benign	0.36	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.63	D
MutationAssessor	Benign	1.3	L;.;.;.;.;.;.;.;.;L;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
PrimateAI	Benign	0.45	T
PROVEAN	Benign	-2.1	N;.;.;N;.;N;.;.;N;N;.;.;.;.;N
REVEL	Uncertain	0.42
Sift	Benign	0.074	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Sift4G	Benign	0.096	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Polyphen		1.0	D;.;.;.;D;D;.;.;D;D;.;.;.;.;.
Vest4		0.47
MutPred		0.22		Loss of phosphorylation at S1096 (P = 0.0128);.;Loss of phosphorylation at S1096 (P = 0.0128);.;.;.;.;Loss of phosphorylation at S1096 (P = 0.0128);.;Loss of phosphorylation at S1096 (P = 0.0128);.;.;.;.;.;
MVP		0.88
ClinPred		0.41	T
GERP RS		4.7
Varity_R		0.15
gMVP		0.52

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

Publications

LitVar

Other links and lift over

dbSNP: rs140772300; hg19: chr16-2129560;