9-32541397-TCA-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PVS1_Moderate PP5

The NM_005802.5(TOPORS):c.3126_3127del(p.Cys1042Ter) variant causes a stop gained, frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000112 in 1,614,054 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000096 (0 hom.)
• Consequence: TOPORS NM_005802.5 stop_gained, frameshift
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 1.96

Genes affected

TOPORS (HGNC:21653): (TOP1 binding arginine/serine rich protein, E3 ubiquitin ligase) This gene encodes a nuclear protein which is serine and arginine rich, and contains a RING-type zinc finger domain. It is highly expressed in the testis, and functions as an ubiquitin-protein E3 ligase. Mutations in this gene are associated with retinitis pigmentosa type 31. Alternatively spliced transcript variants, encoding different isoforms, have been observed for this locus. [provided by RefSeq, Sep 2010]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.00382 CDS is truncated, and there are 0 pathogenic variants in the truncated region.
• PP5: Variant 9-32541397-TCA-T is Pathogenic according to our data. Variant chr9-32541397-TCA-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 940703.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TOPORS	NM_005802.5	c.3126_3127del	p.Cys1042Ter	stop_gained, frameshift_variant	3/3	ENST00000360538.7
TOPORS	NM_001195622.2	c.2931_2932del	p.Cys977Ter	stop_gained, frameshift_variant	2/2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TOPORS	ENST00000360538.7	c.3126_3127del	p.Cys1042Ter	stop_gained, frameshift_variant	3/3	1	NM_005802.5	P3
TOPORS	ENST00000379858.1	c.2931_2932del	p.Cys977Ter	stop_gained, frameshift_variant	2/2	1		A1

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152222 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

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: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000159 AC: 4 AN: 251336 Hom.: 0 AF XY: 0.0000221 AC XY: 3 AN XY: 135824

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000326

GnomAD4 exome AF: 0.00000958 AC: 14 AN: 1461832 Hom.: 0 AF XY: 0.0000124 AC XY: 9 AN XY: 727206

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000447

Gnomad4 ASJ exome AF: 0.0000383

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000809

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152222 Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2 AN XY: 74370

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.000131

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000868 Hom.: 0

Bravo AF: 0.0000529

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jun 09, 2023

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. ClinVar contains an entry for this variant (Variation ID: 940703). This premature translational stop signal has been observed in individuals with clinical features of retinitis pigmentosa (Invitae). This variant is present in population databases (rs776001696, gnomAD 0.003%). This sequence change creates a premature translational stop signal (p.Cys1042*) in the TOPORS gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 4 amino acid(s) of the TOPORS protein. -

Retinitis pigmentosa 31 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

3billion

-

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.002%). The variant is predicted to result in a loss or disruption of normal protein function through protein truncation. The predicted truncated protein may be shortened by less than 10%. Therefore, this variant is classified as Uncertain significance according to the recommendation of ACMG/AMP guideline. -

Computational scores

Source: dbNSFP v4.3

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: rs776001696; hg19: chr9-32541395;