16-2071908-C-T

Variant names:

• chr16-2071908-C-T
• rs760489473
• NM_000548.5:c.2071C>T
• TSC2 p.Arg691Cys

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 2P and 7B. PM1 BP4_Moderate BP6 BS2

The NM_000548.5(TSC2):​c.2071C>T​(p.Arg691Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000584 in 1,593,712 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 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. R691H) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000053 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000059 (0 hom.)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:6
• Conservation: PhyloP100: 0.491
• Publications: 4 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: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, Genomics England PanelApp
• 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.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 8 benign, 34 uncertain in NM_000548.5
• BP4: Computational evidence support a benign effect (MetaRNN=0.25905305).
• BP6: Variant 16-2071908-C-T is Benign according to our data. Variant chr16-2071908-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 184386.
• BS2: High AC in GnomAd4 at 8 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000548.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TSC2	NM_000548.5	MANE Select	c.2071C>T	p.Arg691Cys	missense	Exon 19 of 42	NP_000539.2	P49815-1
	TSC2	NM_001406663.1		c.2071C>T	p.Arg691Cys	missense	Exon 19 of 42	NP_001393592.1	A0A2R8Y6C9
	TSC2	NM_001114382.3		c.2071C>T	p.Arg691Cys	missense	Exon 19 of 41	NP_001107854.1	P49815-4

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TSC2	ENST00000219476.9	TSL:5 MANE Select	c.2071C>T	p.Arg691Cys	missense	Exon 19 of 42	ENSP00000219476.3	P49815-1
	TSC2	ENST00000350773.9	TSL:1	c.2071C>T	p.Arg691Cys	missense	Exon 19 of 41	ENSP00000344383.4	P49815-4
	TSC2	ENST00000401874.7	TSL:1	c.2071C>T	p.Arg691Cys	missense	Exon 19 of 40	ENSP00000384468.2	P49815-5

Frequencies

GnomAD3 genomes AF: 0.0000525 AC: 8 AN: 152254 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000482

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000882

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000663 AC: 14 AN: 211208 AF XY: 0.0000778

Gnomad AFR exome AF: 0.0000791

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000121

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000590 AC: 85 AN: 1441458 Hom.: 0 Cov.: 33 AF XY: 0.0000545 AC XY: 39 AN XY: 715202

African (AFR) AF: 0.0000906 AC: 3 AN: 33096

American (AMR) AF: 0.00 AC: 0 AN: 42568

Ashkenazi Jewish (ASJ) AF: 0.0000390 AC: 1 AN: 25656

East Asian (EAS) AF: 0.00 AC: 0 AN: 38746

South Asian (SAS) AF: 0.0000719 AC: 6 AN: 83410

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 50466

Middle Eastern (MID) AF: 0.000177 AC: 1 AN: 5636

European-Non Finnish (NFE) AF: 0.0000626 AC: 69 AN: 1102408

Other (OTH) AF: 0.0000841 AC: 5 AN: 59472

GnomAD4 genome AF: 0.0000525 AC: 8 AN: 152254 Hom.: 0 Cov.: 33 AF XY: 0.0000672 AC XY: 5 AN XY: 74392

African (AFR) AF: 0.0000482 AC: 2 AN: 41472

American (AMR) AF: 0.00 AC: 0 AN: 15292

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5196

South Asian (SAS) AF: 0.00 AC: 0 AN: 4838

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10632

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000882 AC: 6 AN: 68034

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.0000902 Hom.: 0

Bravo AF: 0.0000529

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	1	2	not provided (3)
-	-	3	Tuberous sclerosis 2 (3)
-	1	1	Hereditary cancer-predisposing syndrome (2)
-	2	-	Tuberous sclerosis syndrome (2)
-	1	-	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.011	T
BayesDel_noAF	Uncertain	-0.030
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.75	D
Eigen	Benign	-0.51
Eigen_PC	Benign	-0.41
FATHMM_MKL	Uncertain	0.79	D
LIST_S2	Uncertain	0.86	D
M_CAP	Uncertain	0.27	D
MetaRNN	Benign	0.26	T
MetaSVM	Benign	-0.29	T
MutationAssessor	Benign	0.90	L
PhyloP100		0.49
PrimateAI	Uncertain	0.54	T
PROVEAN	Uncertain	-3.0	D
REVEL	Uncertain	0.55
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.025	D
Varity_R		0.29
gMVP		0.39
Mutation Taster		=98/2	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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs760489473;

hg19: chr16-2121909;

COSMIC: COSV54782931;