chr9-132927229-A-C

Position:

• chr9-132927229-A-C

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM2 PM5 PP2 PP3_Strong PP5_Moderate

The NM_000368.5(TSC1):​c.182T>G​(p.Leu61Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L61P) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: TSC1 NM_000368.5 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1 O:1
• Conservation: PhyloP100: 9.02

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 Pathogenic. Variant got 11 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr9-132927229-A-G is described in Lovd as [Pathogenic].
• 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.984
• PP5: Variant 9-132927229-A-C is Pathogenic according to our data. Variant chr9-132927229-A-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 64752.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr9-132927229-A-C is described in Lovd as [Pathogenic]. Variant chr9-132927229-A-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TSC1	NM_000368.5	c.182T>G	p.Leu61Arg	missense_variant	4/23	ENST00000298552.9	NP_000359.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TSC1	ENST00000298552.9	c.182T>G	p.Leu61Arg	missense_variant	4/23	1	NM_000368.5	ENSP00000298552	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Tuberous sclerosis 1 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 09, 2016

Experimental studies have shown that this missense change results in reduced TSC1 protein levels, reduced inhibition of TORC1 activity, and altered intracellular expression patterns (PMID: 22161988). A different missense substitution at this codon (p.Leu61Pro) has been also observed in individuals with TSC and has been determined to be likely pathogenic (PMID: 19747374, 21309039). This suggests that the leucine residue is critical for TSC1 protein function. In summary, this variant has been shown to disrupt TSC1 protein function and it occurs at an amino acid position where a different likely pathogenic variant has been previously described. However, the available segregation evidence is limited. For these reasons, this change has been classified as Likely Pathogenic. This variant has been reported in a family affected with tuberous sclerosis complex (TSC) (PMID: 22161988). Although it is reported to co-segregate with disease, details about the family were not provided and, therefore, it is not possible to independently assess this claim. This variant was also observed in another individual diagnosed with TSC (PMID: 22867869). This variant is not present in population databases (rs118203345, ExAC no frequency). This sequence change replaces leucine with arginine at codon 61 of the TSC1 protein (p.Leu61Arg). The leucine residue is highly conserved and there is a moderate physicochemical difference between leucine and arginine. -

Tuberous sclerosis syndrome Other:1

not provided, no classification provided

curation

Tuberous sclerosis database (TSC1)

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.49
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.86	D;.;D;.;D;.;D;.;.;.;.;.;.;.;.;.;.;D;.;.;.
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.88	.;D;D;D;.;.;.;D;D;.;D;.;.;T;T;T;D;T;T;D;D
M_CAP	Pathogenic	0.70	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.5	M;M;M;.;M;.;M;.;.;M;.;.;.;.;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.69	T
PROVEAN	Pathogenic	-5.1	D;D;D;.;.;.;.;.;.;.;.;.;.;.;.;.;.;D;.;.;.
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D;D;D;.;.;.;.;.;.;.;.;.;.;.;.;.;.;D;.;.;.
Sift4G	Pathogenic	0.0	D;D;D;.;.;.;.;.;.;.;.;.;.;.;.;.;.;D;.;.;.
Polyphen		1.0	D;.;D;.;D;.;D;.;.;.;.;D;D;D;.;.;.;D;.;.;.
Vest4		0.99
MutPred		0.88		Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);
MVP		0.96
MPC		1.7
ClinPred		1.0	D
GERP RS		5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
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

LitVar

Other links and lift over

dbSNP: rs118203345; hg19: chr9-135802616;