16-2071846-C-A

Variant names:

• chr16-2071846-C-A
• rs397515288
• NM_000548.5:c.2009C>A

Variant summary

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

The NM_000548.5(TSC2):​c.2009C>A​(p.Pro670His) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. P670L) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.44

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.2009C>A	p.Pro670His	missense_variant	Exon 19 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.2009C>A	p.Pro670His	missense_variant	Exon 19 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1429460 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 708244

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

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

Nov 15, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.P670H variant (also known as c.2009C>A), located in coding exon 18 of the TSC2 gene, results from a C to A substitution at nucleotide position 2009. The proline at codon 670 is replaced by histidine, an amino acid with similar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Benign	-0.090
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.83	D;.;.;.;.;.;.;.;.;.;.;.;D;.;D
Eigen	Benign	0.17
Eigen_PC	Benign	0.056
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Uncertain	0.92	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.38	D
MetaRNN	Uncertain	0.62	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.65	D
MutationAssessor	Uncertain	2.1	M;.;.;.;M;M;.;.;.;M;.;M;.;.;.
PrimateAI	Benign	0.45	T
PROVEAN	Uncertain	-3.2	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
REVEL	Uncertain	0.45
Sift	Uncertain	0.0050	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Sift4G	Uncertain	0.0020	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Polyphen		1.0	D;.;.;.;P;P;.;.;P;P;.;.;.;.;.
Vest4		0.45
MutPred		0.42		Loss of glycosylation at P670 (P = 0.0044);Loss of glycosylation at P670 (P = 0.0044);Loss of glycosylation at P670 (P = 0.0044);.;Loss of glycosylation at P670 (P = 0.0044);Loss of glycosylation at P670 (P = 0.0044);Loss of glycosylation at P670 (P = 0.0044);Loss of glycosylation at P670 (P = 0.0044);.;Loss of glycosylation at P670 (P = 0.0044);Loss of glycosylation at P670 (P = 0.0044);Loss of glycosylation at P670 (P = 0.0044);Loss of glycosylation at P670 (P = 0.0044);Loss of glycosylation at P670 (P = 0.0044);.;
MVP		0.92
ClinPred		0.96	D
GERP RS		5.4
Varity_R		0.17
gMVP		0.52

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: rs397515288; hg19: chr16-2121847;