Variant 17-18274921-T-C details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_004618.5(TOP3A):c.2887A>G(p.Arg963Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,882 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 30)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

TOP3A
NM_004618.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.22

Variant links:

Genes affected

TOP3A (HGNC:11992): (DNA topoisomerase III alpha) This gene encodes a DNA topoisomerase, an enzyme that controls and alters the topologic states of DNA during transcription. This enzyme catalyzes the transient breaking and rejoining of a single strand of DNA which allows the strands to pass through one another, thus reducing the number of supercoils and altering the topology of DNA. This enzyme forms a complex with BLM which functions in the regulation of recombination in somatic cells. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Mar 2016]

TOP3A links:

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ACMG classification

Classification made for transcript

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=0.10002169).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TOP3A	NM_004618.5 link	c.2887A>G	p.Arg963Gly	missense_variant	Exon 19 of 19	ENST00000321105.10	NP_004609.1	Q13472-1
TOP3A	NM_001320759.2 link	c.2602A>G	p.Arg868Gly	missense_variant	Exon 18 of 18		NP_001307688.1	Q13472-3
TOP3A	XM_047436633.1 link	c.1966A>G	p.Arg656Gly	missense_variant	Exon 17 of 17		XP_047292589.1
TOP3A	XM_047436634.1 link	c.1966A>G	p.Arg656Gly	missense_variant	Exon 17 of 17		XP_047292590.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TOP3A	ENST00000321105.10 link	c.2887A>G	p.Arg963Gly	missense_variant	Exon 19 of 19	1	NM_004618.5	ENSP00000321636.5		Q13472-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251488

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135920

show subpopulations

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:

6.84e-7

AC:

AN:

1461882

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727242

show subpopulations

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:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Bravo

AF:

0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Apr 18, 2023

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. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant¬¨‚Ä† is likely to be tolerated. This variant has not been reported in the literature in individuals affected with TOP3A-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.003%). This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 963 of the TOP3A protein (p.Arg963Gly). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.073

BayesDel_addAF

Benign

-0.28

BayesDel_noAF

Benign

-0.55

CADD

Benign

DANN

Benign

0.67

DEOGEN2

Benign

0.029

T;T;.

Eigen

Benign

-0.62

Eigen_PC

Benign

-0.51

FATHMM_MKL

Uncertain

0.88

M_CAP

Benign

0.0066

MetaRNN

Benign

0.10

T;T;T

MetaSVM

Benign

-0.99

MutationAssessor

Benign

1.6

L;L;.

PrimateAI

Benign

0.35

PROVEAN

Benign

0.53

.;N;.

REVEL

Benign

0.044

Sift

Benign

0.48

.;T;.

Sift4G

Benign

0.51

T;T;.

Polyphen

0.0

B;B;.

Vest4

0.062

MutPred

0.22

Loss of MoRF binding (P = 0.0183);Loss of MoRF binding (P = 0.0183);.;

MVP

0.15

MPC

0.23

ClinPred

0.051

GERP RS

3.4

Varity_R

0.057

gMVP

0.25

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over