chr16-2079149-C-A

Variant names:

• chr16-2079149-C-A
• rs1555510350
• NM_000548.5:c.3084C>A

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP3_Moderate

The NM_000548.5(TSC2):​c.3084C>A​(p.Asp1028Glu) 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 1,460,738 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 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. D1028G) has been classified as Uncertain significance.

• 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
• Conservation: PhyloP100: 0.286
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• tuberous sclerosis

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• tuberous sclerosis 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, Ambry Genetics
• lymphangioleiomyomatosis

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• tuberous sclerosis complex

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 15 uncertain in NM_000548.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr16-2079147-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 49547.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.857

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.3084C>A	p.Asp1028Glu	missense_variant	Exon 27 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.3084C>A	p.Asp1028Glu	missense_variant	Exon 27 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460738 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726650

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52286

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112006

Other (OTH) AF: 0.00 AC: 0 AN: 60382

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Jun 23, 2020

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.D1028E variant (also known as c.3084C>A), located in coding exon 26 of the TSC2 gene, results from a C to A substitution at nucleotide position 3084. The aspartic acid at codon 1028 is replaced by glutamic acid, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. 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	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.48
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.90	D;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Uncertain	0.48
Eigen_PC	Uncertain	0.40
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Uncertain	0.95	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.53	D
MetaRNN	Pathogenic	0.86	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.8	M;.;.;.;.;.;.;.;.;M;.;.;.;.;.
PhyloP100		0.29
PrimateAI	Pathogenic	0.80	T
PROVEAN	Uncertain	-3.8	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
REVEL	Pathogenic	0.83
Sift	Pathogenic	0.0	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Sift4G	Benign	0.072	T;.;.;D;.;D;.;.;D;T;.;.;.;.;D
Polyphen		0.99	D;.;.;.;D;D;.;.;D;D;.;.;.;.;.
Vest4		0.97
MutPred		0.50		Gain of catalytic residue at D1028 (P = 0.2126);.;Gain of catalytic residue at D1028 (P = 0.2126);.;.;.;.;Gain of catalytic residue at D1028 (P = 0.2126);.;Gain of catalytic residue at D1028 (P = 0.2126);.;.;.;.;.;
MVP		1.0
ClinPred		0.99	D
GERP RS		2.8
Varity_R		0.91
gMVP		0.90
Mutation Taster		=48/52	disease causing

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

Other links and lift over

dbSNP: rs1555510350; hg19: chr16-2129150;