17-18274905-C-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_004618.5(TOP3A):c.2903G>A(p.Arg968Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000102 in 1,613,990 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. 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. R968P) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 31)

Exomes 𝑓: 0.00011 ( 0 hom. )

Consequence

TOP3A
NM_004618.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.28

Publications

0 publications found

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 Gene-Disease associations (from GenCC):

microcephaly, growth restriction, and increased sister chromatid exchange 2
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P
progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal recessive 5
Inheritance: AR Classification: STRONG, LIMITED Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae)

TOP3A links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.07838273).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004618.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TOP3A	NM_004618.5	MANE Select	c.2903G>A	p.Arg968Gln	missense	Exon 19 of 19	NP_004609.1	Q13472-1
	TOP3A	NM_001320759.2		c.2618G>A	p.Arg873Gln	missense	Exon 18 of 18	NP_001307688.1	Q13472-3

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
TOP3A	ENST00000321105.10	TSL:1 MANE Select	c.2903G>A	p.Arg968Gln	missense	Exon 19 of 19	ENSP00000321636.5	Q13472-1
TOP3A	ENST00000580095.5	TSL:1	c.2828G>A	p.Arg943Gln	missense	Exon 19 of 19	ENSP00000462790.1	Q13472-2
TOP3A	ENST00000924978.1		c.3059G>A	p.Arg1020Gln	missense	Exon 20 of 20	ENSP00000595037.1

Frequencies

GnomAD3 genomes

AF:

0.0000526

AC:

AN:

152104

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000656

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000103

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000477

AC:

AN:

251492

AF XY:

0.0000294

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000107

AC:

156

AN:

1461886

Hom.:

Cov.:

AF XY:

0.000103

AC XY:

AN XY:

727240

show subpopulations

African (AFR)

AF:

0.0000896

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53418

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.000132

AC:

147

AN:

1112010

Other (OTH)

AF:

0.0000828

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.465

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000526

AC:

AN:

152104

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74306

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41420

American (AMR)

AF:

0.0000656

AC:

AN:

15250

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4818

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10610

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000103

AC:

AN:

68026

Other (OTH)

AF:

0.00

AC:

AN:

2088

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.519

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000823

Hom.:

Bravo

AF:

0.0000680

ExAC

AF:

0.0000659

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

ClinVar submissions

Significance:Uncertain significance

Revision:criteria provided, single submitter

View on ClinVar

Pathogenic

VUS

Benign

Condition

not provided (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.080

BayesDel_addAF

Benign

-0.44

BayesDel_noAF

Benign

-0.63

CADD

Benign

(source)

DANN

Benign

0.69

DEOGEN2

Benign

0.046

Eigen

Benign

-0.51

Eigen_PC

Benign

-0.55

FATHMM_MKL

Benign

0.16

M_CAP

Benign

0.014

MetaRNN

Benign

0.078

MetaSVM

Benign

-1.0

MutationAssessor

Uncertain

2.4

PhyloP100

1.3

PrimateAI

Benign

0.33

PROVEAN

Benign

-0.71

REVEL

Benign

0.037

Sift

Benign

0.34

Sift4G

Benign

0.60

Polyphen

0.54

Vest4

0.062

MVP

0.15

MPC

0.25

ClinPred

0.067

GERP RS

4.7

PromoterAI

0.031

Neutral

(source)

Varity_R

0.044

gMVP

0.28

Mutation Taster

=93/7

polymorphism

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over