16-2054390-A-G

Variant names:

• chr16-2054390-A-G
• rs769286175
• NM_000548.5:c.431A>G

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP6 BS2

The NM_000548.5(TSC2):​c.431A>G​(p.Lys144Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000616 in 1,461,884 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K144M) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:3
• Conservation: PhyloP100: 7.22
• Publications: 6 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_benign. The variant received -5 ACMG points.

• BP6: Variant 16-2054390-A-G is Benign according to our data. Variant chr16-2054390-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 207700.We mark this variant Likely_benign, oryginal submission is: [Conflicting_classifications_of_pathogenicity].
• BS2: High AC in GnomAdExome4 at 9 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.431A>G	p.Lys144Arg	missense_variant	Exon 5 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.431A>G	p.Lys144Arg	missense_variant	Exon 5 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.0000278 AC: 7 AN: 251488 AF XY: 0.0000294

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000352

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000616 AC: 9 AN: 1461884 Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5 AN XY: 727240

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

American (AMR) AF: 0.0000447 AC: 2 AN: 44724

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

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

South Asian (SAS) AF: 0.0000232 AC: 2 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

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

European-Non Finnish (NFE) AF: 0.00000450 AC: 5 AN: 1112008

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000293 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.0000412 AC: 5

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Tuberous sclerosis 2 Benign:2

Nov 07, 2021

Genome-Nilou Lab

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dec 17, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Tuberous sclerosis syndrome Uncertain:1

May 04, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces lysine with arginine at codon 144 of the TSC2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with tuberous sclerosis complex in the literature. This variant has been identified in 7/251488 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Hereditary cancer-predisposing syndrome Uncertain:1

Mar 03, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.K144R variant (also known as c.431A>G), located in coding exon 4 of the TSC2 gene, results from an A to G substitution at nucleotide position 431. The lysine at codon 144 is replaced by arginine, an amino acid with highly similar properties. This variant has been detected in multiple individuals with no reported features of tuberous sclerosis complex (Ambry internal data). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -

not specified Benign:1

Nov 17, 2017

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Pathogenic	0.16	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.53	D;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Uncertain	0.38
Eigen_PC	Uncertain	0.40
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.84	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
M_CAP	Pathogenic	0.30	D
MetaRNN	Uncertain	0.58	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.083	D
MutationAssessor	Benign	1.8	L;.;.;.;L;L;.;.;.;L;.;L;.;.;.
PhyloP100		7.2
PrimateAI	Uncertain	0.59	T
PROVEAN	Benign	-2.0	N;.;.;N;.;N;.;.;N;N;.;.;.;.;N
REVEL	Pathogenic	0.67
Sift	Uncertain	0.020	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Sift4G	Benign	0.18	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Polyphen		0.99	D;.;.;.;.;P;.;.;D;B;.;.;.;.;.
Vest4		0.56
MutPred		0.36		Loss of ubiquitination at K144 (P = 0.0155);Loss of ubiquitination at K144 (P = 0.0155);Loss of ubiquitination at K144 (P = 0.0155);.;Loss of ubiquitination at K144 (P = 0.0155);Loss of ubiquitination at K144 (P = 0.0155);Loss of ubiquitination at K144 (P = 0.0155);Loss of ubiquitination at K144 (P = 0.0155);.;Loss of ubiquitination at K144 (P = 0.0155);Loss of ubiquitination at K144 (P = 0.0155);Loss of ubiquitination at K144 (P = 0.0155);Loss of ubiquitination at K144 (P = 0.0155);Loss of ubiquitination at K144 (P = 0.0155);.;
MVP		0.89
ClinPred		0.52	D
GERP RS		5.0
Varity_R		0.29
gMVP		0.38
Mutation Taster		=78/22	polymorphism

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

Other links and lift over

dbSNP: rs769286175; hg19: chr16-2104391;