8-143310063-C-A

Variant names:

• chr8-143310063-C-A
• NM_052963.3:c.1703+5G>T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_052963.3(TOP1MT):​c.1703+5G>T variant causes a splice region, intron 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: TOP1MT NM_052963.3 splice_region, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.422
• Publications: 0 publications found

Genes affected

TOP1MT (HGNC:29787): (DNA topoisomerase I mitochondrial) This gene encodes a mitochondrial DNA topoisomerase that plays a role in the modification of DNA topology. The encoded protein is a type IB topoisomerase and catalyzes the transient breaking and rejoining of DNA to relieve tension and DNA supercoiling generated in the mitochondrial genome during replication and transcription. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. [provided by RefSeq, May 2012]

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_052963.3. 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
	TOP1MT	NM_052963.3	MANE Select	c.1703+5G>T		splice_region intron	N/A	NP_443195.1	Q969P6-1
	TOP1MT	NM_001258446.1		c.1409+5G>T		splice_region intron	N/A	NP_001245375.1	Q969P6-2
	TOP1MT	NM_001258447.1		c.1409+5G>T		splice_region intron	N/A	NP_001245376.1	Q969P6-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TOP1MT	ENST00000329245.9	TSL:1 MANE Select	c.1703+5G>T		splice_region intron	N/A	ENSP00000328835.3	Q969P6-1
	TOP1MT	ENST00000969804.1		c.1793+5G>T		splice_region intron	N/A	ENSP00000639863.1
	TOP1MT	ENST00000870174.1		c.1703+5G>T		splice_region intron	N/A	ENSP00000540233.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 37

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.72
CADD	Benign	11
DANN	Benign	0.85
PhyloP100		0.42
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.87
SpliceAI score (max)		0.65		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.65		Position offset: 5

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

hg19: chr8-144392233;