16-2088445-G-C

Variant names:

• chr16-2088445-G-C
• rs1057518103
• NM_000548.5:c.5260-1G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_Strong PM2

The NM_000548.5(TSC2):​c.5260-1G>C variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000263 in 152,192 control chromosomes in the GnomAD database, with no homozygous occurrence. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: 𝑓 0.000026 (0 hom., cov: 33)
• Consequence: TSC2 NM_000548.5 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:7 B:2
• Conservation: PhyloP100: 7.43
• Publications: 1 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: Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, 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 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.19284661 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.8, offset of -30, new splice context is: gcggttgccacgcctcccAGact. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage

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.5260-1G>C		splice_acceptor intron	N/A	NP_000539.2	P49815-1
	TSC2	NM_001406663.1		c.5257-1G>C		splice_acceptor intron	N/A	NP_001393592.1	A0A2R8Y6C9
	TSC2	NM_001114382.3		c.5191-1G>C		splice_acceptor intron	N/A	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.5260-1G>C		splice_acceptor intron	N/A	ENSP00000219476.3	P49815-1
	TSC2	ENST00000350773.9	TSL:1	c.5191-1G>C		splice_acceptor intron	N/A	ENSP00000344383.4	P49815-4
	TSC2	ENST00000401874.7	TSL:1	c.5059-1G>C		splice_acceptor intron	N/A	ENSP00000384468.2	P49815-5

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152192 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000483

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: 0.0000294

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 33

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152192 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74350

African (AFR) AF: 0.0000483 AC: 2 AN: 41436

American (AMR) AF: 0.00 AC: 0 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3466

East Asian (EAS) AF: 0.00 AC: 0 AN: 5192

South Asian (SAS) AF: 0.00 AC: 0 AN: 4836

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

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

European-Non Finnish (NFE) AF: 0.0000294 AC: 2 AN: 68048

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.0000283 Hom.: 0

Bravo AF: 0.0000227

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	3	-	not provided (3)
-	1	1	Tuberous sclerosis 2 (2)
-	-	1	Hereditary cancer-predisposing syndrome (1)
-	1	-	Isolated focal cortical dysplasia type II (1)
-	1	-	Lymphangiomyomatosis;C1846385:Isolated focal cortical dysplasia type II;C1860707:Tuberous sclerosis 2 (1)
-	1	-	Tuberous sclerosis syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Uncertain	0.032	T
BayesDel_noAF	Benign	-0.19
CADD	Pathogenic	31
DANN	Uncertain	0.99
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.97	D
PhyloP100		7.4
GERP RS		4.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.84
SpliceAI score (max)		0.97		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.22		Position offset: 14
DS_AL_spliceai		0.97		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1057518103; hg19: chr16-2138446;