chr9-132896662-G-A

Position:

• chr9-132896662-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 3P and 3B. PM2 PP2 BP4_Moderate BP6

The NM_000368.5(TSC1):​c.3068C>T​(p.Pro1023Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,798 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict 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. P1023S) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: TSC1 NM_000368.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 3.34

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 0 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.08062801).
• BP6: Variant 9-132896662-G-A is Benign according to our data. Variant chr9-132896662-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 466116.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Benign=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TSC1	NM_000368.5	c.3068C>T	p.Pro1023Leu	missense_variant	23/23	ENST00000298552.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TSC1	ENST00000298552.9	c.3068C>T	p.Pro1023Leu	missense_variant	23/23	1	NM_000368.5	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461798 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727200

Gnomad4 AFR exome AF: 0.0000299

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: 0.0000331

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 18, 2023

The p.P1023L variant (also known as c.3068C>T), located in coding exon 21 of the TSC1 gene, results from a C to T substitution at nucleotide position 3068. The proline at codon 1023 is replaced by leucine, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Tuberous sclerosis 1 Benign:1

Benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 30, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.076
BayesDel_addAF	Benign	-0.070	T
BayesDel_noAF	Benign	-0.34
CADD	Benign	20
DANN	Uncertain	0.99
DEOGEN2	Benign	0.33	T;.;T;.;.;T;.;T;.;.;.
Eigen	Benign	-0.32
Eigen_PC	Benign	-0.28
FATHMM_MKL	Uncertain	0.78	D
LIST_S2	Benign	0.72	.;T;T;T;T;.;.;.;T;T;.
M_CAP	Uncertain	0.093	D
MetaRNN	Benign	0.081	T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.59	T
MutationAssessor	Uncertain	2.3	M;.;M;.;.;M;.;M;.;.;.
MutationTaster	Benign	1.0	D;D;D;N
PrimateAI	Benign	0.34	T
PROVEAN	Benign	-0.46	N;N;N;.;.;.;.;.;.;.;.
REVEL	Benign	0.17
Sift	Benign	0.087	T;T;T;.;.;.;.;.;.;.;.
Sift4G	Uncertain	0.018	D;D;D;.;.;.;.;.;.;.;.
Polyphen		0.0010	B;.;B;.;.;B;.;B;.;.;.
Vest4		0.029
MutPred		0.25		Loss of glycosylation at P1023 (P = 0.0317);.;Loss of glycosylation at P1023 (P = 0.0317);.;.;Loss of glycosylation at P1023 (P = 0.0317);.;Loss of glycosylation at P1023 (P = 0.0317);.;.;.;
MVP		0.44
MPC		0.51
ClinPred		0.41	T
GERP RS		3.6
Varity_R		0.033
gMVP		0.22

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: rs1554812917; hg19: chr9-135772049;