rs397514914

Positions:

• chr16-2071534-C-G
• chr16-2071534-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PM5 PP3_Strong

The NM_000548.5(TSC2):​c.1864C>G​(p.Arg622Gly) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,296 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 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. R622P) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.75

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 Likely_pathogenic. Variant got 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr16-2071535-G-C is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.944

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TSC2	NM_000548.5	c.1864C>G	p.Arg622Gly	missense_variant	18/42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.1864C>G	p.Arg622Gly	missense_variant	18/42	5	NM_000548.5	ENSP00000219476

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461296 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 726972

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: 8.99e-7

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 08, 2024

The p.R622G variant (also known as c.1864C>G), located in coding exon 17 of the TSC2 gene, results from a C to G substitution at nucleotide position 1864. The arginine at codon 622 is replaced by glycine, an amino acid with dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. The evidence for this gene-disease relationship is limited; therefore, the clinical significance of this alteration is unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.82
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.43
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.94	D;.;.;.;.;.;.;.;.;.;.;.;D;.;D
Eigen	Uncertain	0.61
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.93	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.75	D
MetaRNN	Pathogenic	0.94	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.92	D
MutationAssessor	Pathogenic	3.0	M;.;.;.;M;M;.;.;.;M;.;M;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
PrimateAI	Uncertain	0.63	T
PROVEAN	Pathogenic	-6.3	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
REVEL	Pathogenic	0.92
Sift	Pathogenic	0.0	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Sift4G	Pathogenic	0.0	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Polyphen		1.0	D;.;.;.;D;D;.;.;D;D;.;.;.;.;.
Vest4		0.90
MutPred		0.79		Gain of loop (P = 0.0097);Gain of loop (P = 0.0097);Gain of loop (P = 0.0097);.;Gain of loop (P = 0.0097);Gain of loop (P = 0.0097);Gain of loop (P = 0.0097);Gain of loop (P = 0.0097);.;Gain of loop (P = 0.0097);Gain of loop (P = 0.0097);Gain of loop (P = 0.0097);Gain of loop (P = 0.0097);Gain of loop (P = 0.0097);.;
MVP		0.99
ClinPred		0.99	D
GERP RS		4.5
Varity_R		0.92
gMVP		0.93

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr16-2121535;