9-132896464-C-T

Position:

• chr9-132896464-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The ENST00000298552.9(TSC1):​c.3266G>A​(p.Gly1089Asp) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,892 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. G1089A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TSC1 ENST00000298552.9 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.36

Genes affected

TSC1 (HGNC:12362): (TSC complex subunit 1) This gene is a tumor suppressor gene that encodes the growth inhibitory protein hamartin. The encoded protein interacts with and stabilizes the GTPase activating protein tuberin. This hamartin-tuberin complex negatively regulates mammalian target of rapamycin complex 1 (mTORC1) signaling which is a major regulator of anabolic cell growth. This protein also functions as a co-chaperone for Hsp90 that inhibits its ATPase activity. This protein functions as a facilitator of Hsp90-mediated folding of kinase and non-kinase clients, including TSC2 and thereby preventing their ubiquitination and proteasomal degradation. 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 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), TSC1. . Gene score misZ 2.3217 (greater than the threshold 3.09). Trascript score misZ 3.6986 (greater than threshold 3.09). GenCC has associacion of gene with lung lymphangioleiomyomatosis, tuberous sclerosis 1, tuberous sclerosis, tuberous sclerosis complex, lymphangioleiomyomatosis.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TSC1	NM_000368.5	c.3266G>A	p.Gly1089Asp	missense_variant	23/23	ENST00000298552.9	NP_000359.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TSC1	ENST00000298552.9	c.3266G>A	p.Gly1089Asp	missense_variant	23/23	1	NM_000368.5	ENSP00000298552	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251470 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135908

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461892 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727248

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.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Tuberous sclerosis 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 01, 2018

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with TSC1-related disease. This variant is present in population databases (rs762845573, ExAC 0.001%). This sequence change replaces glycine with aspartic acid at codon 1089 of the TSC1 protein (p.Gly1089Asp). The glycine residue is highly conserved and there is a moderate physicochemical difference between glycine and aspartic acid. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.32	D
BayesDel_noAF	Pathogenic	0.22
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.47	T;.;T;.;.;T;.;T;.;.;.
Eigen	Benign	0.14
Eigen_PC	Uncertain	0.28
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.94	.;D;D;D;D;.;.;.;D;D;.
M_CAP	Uncertain	0.11	D
MetaRNN	Uncertain	0.64	D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	-0.22	T
MutationAssessor	Uncertain	2.3	M;.;M;.;.;M;.;M;.;.;.
MutationTaster	Benign	1.0	D;D;D;N
PrimateAI	Pathogenic	0.83	D
PROVEAN	Benign	-1.7	N;N;N;.;.;.;.;.;.;.;.
REVEL	Pathogenic	0.71
Sift	Uncertain	0.0020	D;D;D;.;.;.;.;.;.;.;.
Sift4G	Uncertain	0.0040	D;D;D;.;.;.;.;.;.;.;.
Polyphen		0.98	D;.;D;.;.;D;.;D;.;.;.
Vest4		0.65
MutPred		0.38		Gain of ubiquitination at K1091 (P = 0.0177);.;Gain of ubiquitination at K1091 (P = 0.0177);.;.;Gain of ubiquitination at K1091 (P = 0.0177);.;Gain of ubiquitination at K1091 (P = 0.0177);.;.;.;
MVP		0.90
MPC		1.6
ClinPred		0.86	D
GERP RS		3.6
Varity_R		0.41
gMVP		0.68

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: rs762845573; hg19: chr9-135771851;