16-2088539-A-T

Variant names:

• chr16-2088539-A-T
• rs1555441455
• NM_000548.5:c.5353A>T

Variant summary

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

The NM_000548.5(TSC2):​c.5353A>T​(p.Thr1785Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.868

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]

PKD1 (HGNC:9008): (polycystin 1, transient receptor potential channel interacting) This gene encodes a member of the polycystin protein family. The encoded glycoprotein contains a large N-terminal extracellular region, multiple transmembrane domains and a cytoplasmic C-tail. It is an integral membrane protein that functions as a regulator of calcium permeable cation channels and intracellular calcium homoeostasis. It is also involved in cell-cell/matrix interactions and may modulate G-protein-coupled signal-transduction pathways. It plays a role in renal tubular development, and mutations in this gene cause autosomal dominant polycystic kidney disease type 1 (ADPKD1). ADPKD1 is characterized by the growth of fluid-filled cysts that replace normal renal tissue and result in end-stage renal failure. Splice variants encoding different isoforms have been noted for this gene. Also, six pseudogenes, closely linked in a known duplicated region on chromosome 16p, have been described. [provided by RefSeq, Oct 2008]

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=0.06863427).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.5353A>T	p.Thr1785Ser	missense_variant	Exon 42 of 42	ENST00000219476.9	NP_000539.2
PKD1	NM_001009944.3	c.*1188T>A		downstream_gene_variant		ENST00000262304.9	NP_001009944.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.5353A>T	p.Thr1785Ser	missense_variant	Exon 42 of 42	5	NM_000548.5	ENSP00000219476.3
PKD1	ENST00000262304.9	c.*1188T>A		downstream_gene_variant		1	NM_001009944.3	ENSP00000262304.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Tuberous sclerosis 2 Uncertain:1

Dec 04, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, this variant has uncertain impact on TSC2 function. The available evidence is currently insufficient to determine its role in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with a TSC2-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces threonine with serine at codon 1785 of the TSC2 protein (p.Thr1785Ser). The threonine residue is weakly conserved and there is a small physicochemical difference between threonine and serine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.073
BayesDel_addAF	Uncertain	0.017	T
BayesDel_noAF	Benign	-0.21
CADD	Benign	0.018
DANN	Benign	0.54
DEOGEN2	Benign	0.35	T;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Benign	-1.6
Eigen_PC	Benign	-1.6
FATHMM_MKL	Benign	0.10	N
LIST_S2	Benign	0.85	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
M_CAP	Benign	0.069	D
MetaRNN	Benign	0.069	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.66	T
MutationAssessor	Benign	1.5	L;.;.;.;.;.;.;.;.;.;.;.;.;.;.
PrimateAI	Benign	0.24	T
PROVEAN	Benign	-0.13	N;.;.;N;.;N;.;.;N;N;.;.;.;.;N
REVEL	Uncertain	0.48
Sift	Benign	0.14	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Sift4G	Benign	0.75	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Polyphen		0.13	B;.;.;.;B;B;.;.;B;B;.;.;.;.;.
Vest4		0.15
MutPred		0.23		Gain of relative solvent accessibility (P = 0.0166);.;.;.;.;.;.;.;.;.;.;.;.;.;.;
MVP		0.82
ClinPred		0.073	T
GERP RS		-4.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.040
gMVP		0.37

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: rs1555441455; hg19: chr16-2138540;