9-132900726-C-T

Variant names:

• chr9-132900726-C-T
• rs746607455
• NM_000368.5:c.2614G>A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000368.5(TSC1):​c.2614G>A​(p.Asp872Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,840 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: TSC1 NM_000368.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 2.91

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
• BP4: Computational evidence support a benign effect (MetaRNN=0.19853863).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC1	NM_000368.5	c.2614G>A	p.Asp872Asn	missense_variant	Exon 20 of 23	ENST00000298552.9	NP_000359.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC1	ENST00000298552.9	c.2614G>A	p.Asp872Asn	missense_variant	Exon 20 of 23	1	NM_000368.5	ENSP00000298552.3
TSC1	ENST00000490179.4	c.2614G>A	p.Asp872Asn	missense_variant	Exon 21 of 24	3		ENSP00000495533.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251478 Hom.: 0 AF XY: 0.00000736 AC XY: 1 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: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461840 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727224

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: 0.0000116

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:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Tuberous sclerosis syndrome Uncertain:1

May 31, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Tuberous sclerosis 1 Uncertain:1

Aug 21, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with TSC1-related conditions. This variant is present in population databases (rs746607455, ExAC 0.006%). This sequence change replaces aspartic acid with asparagine at codon 872 of the TSC1 protein (p.Asp872Asn). The aspartic acid residue is moderately conserved and there is a small physicochemical difference between aspartic acid and asparagine. -

Hereditary cancer-predisposing syndrome Uncertain:1

Oct 12, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.D872N variant (also known as c.2614G>A), located in coding exon 18 of the TSC1 gene, results from a G to A substitution at nucleotide position 2614. The aspartic acid at codon 872 is replaced by asparagine, an amino acid with highly similar properties. This amino acid position is conserved. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.15	T
BayesDel_noAF	Benign	-0.36
CADD	Uncertain	23
DANN	Uncertain	1.0
DEOGEN2	Benign	0.33	T;.;T;.;.;T;.;T;.;.;.
Eigen	Uncertain	0.32
Eigen_PC	Uncertain	0.39
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.89	.;D;D;D;D;.;.;.;D;D;.
M_CAP	Benign	0.054	D
MetaRNN	Benign	0.20	T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.40	T
MutationAssessor	Benign	1.2	L;.;L;.;.;L;.;L;.;.;.
PrimateAI	Uncertain	0.58	T
PROVEAN	Benign	-0.47	N;N;N;.;.;.;.;.;.;.;.
REVEL	Uncertain	0.30
Sift	Benign	0.38	T;T;T;.;.;.;.;.;.;.;.
Sift4G	Benign	0.24	T;T;T;.;.;.;.;.;.;.;.
Polyphen		0.78	P;.;P;.;.;P;.;P;.;.;.
Vest4		0.34
MutPred		0.12		Gain of MoRF binding (P = 0.0502);.;Gain of MoRF binding (P = 0.0502);.;.;Gain of MoRF binding (P = 0.0502);.;Gain of MoRF binding (P = 0.0502);.;.;.;
MVP		0.82
MPC		0.55
ClinPred		0.44	T
GERP RS		5.6
Varity_R		0.38
gMVP		0.16

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: rs746607455; hg19: chr9-135776113;