chr3-25598337-T-C

Variant names:

• chr3-25598337-T-C
• rs61739570
• NM_001330700.2:c.4851A>G

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_001330700.2(TOP2B):​c.4851A>G​(p.Glu1617Glu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 33)
• Consequence: TOP2B NM_001330700.2 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.487
• Publications: 10 publications found

Genes affected

TOP2B (HGNC:11990): (DNA topoisomerase II beta) This gene encodes a DNA topoisomerase, an enzyme that controls and alters the topologic states of DNA during transcription. This nuclear enzyme is involved in processes such as chromosome condensation, chromatid separation, and the relief of torsional stress that occurs during DNA transcription and replication. It catalyzes the transient breaking and rejoining of two strands of duplex DNA which allows the strands to pass through one another, thus altering the topology of DNA. Two forms of this enzyme exist as likely products of a gene duplication event. The gene encoding this form, beta, is localized to chromosome 3 and the alpha form is localized to chromosome 17. The gene encoding this enzyme functions as the target for several anticancer agents and a variety of mutations in this gene have been associated with the development of drug resistance. Reduced activity of this enzyme may also play a role in ataxia-telangiectasia. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2016]

TOP2B Gene-Disease associations (from GenCC):

• B-cell immunodeficiency, distal limb anomalies, and urogenital malformations

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: ClinGen, Illumina, Ambry Genetics, PanelApp Australia
• neurodevelopmental disorder

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.69).
• BP7: Synonymous conserved (PhyloP=-0.487 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001330700.2. 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
	TOP2B	NM_001330700.2	MANE Select	c.4851A>G	p.Glu1617Glu	synonymous	Exon 36 of 36	NP_001317629.1	Q02880-1
	TOP2B	NM_001068.3		c.4836A>G	p.Glu1612Glu	synonymous	Exon 36 of 36	NP_001059.2	Q59H80

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TOP2B	ENST00000264331.9	TSL:5 MANE Select	c.4851A>G	p.Glu1617Glu	synonymous	Exon 36 of 36	ENSP00000264331.4	Q02880-1
	TOP2B	ENST00000435706.7	TSL:1	c.4836A>G	p.Glu1612Glu	synonymous	Exon 36 of 36	ENSP00000396704.2
	TOP2B	ENST00000424225.2	TSL:1	c.4752A>G	p.Glu1584Glu	synonymous	Exon 36 of 36	ENSP00000391112.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 37

Bravo AF: 0.00000378

EpiCase AF: 0.0000547

EpiControl AF: 0.00

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.69
CADD	Benign	0.093
DANN	Benign	0.46
PhyloP100		-0.49
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.8

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

Other links and lift over

dbSNP: rs61739570; hg19: chr3-25639828;