chr14-89993420-A-G

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM2PP3_StrongPP5_Very_Strong

The NM_018319.4(TDP1):c.1478A>G(p.His493Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000806 in 1,613,830 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000068 ( 0 hom. )

Consequence

TDP1
NM_018319.4 missense

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 7.89

Variant links:

Genes affected

TDP1 (HGNC:18884): (tyrosyl-DNA phosphodiesterase 1) The protein encoded by this gene is involved in repairing stalled topoisomerase I-DNA complexes by catalyzing the hydrolysis of the phosphodiester bond between the tyrosine residue of topoisomerase I and the 3-prime phosphate of DNA. This protein may also remove glycolate from single-stranded DNA containing 3-prime phosphoglycolate, suggesting a role in repair of free-radical mediated DNA double-strand breaks. This gene is a member of the phospholipase D family and contains two PLD phosphodiesterase domains. Mutations in this gene are associated with the disease spinocerebellar ataxia with axonal neuropathy (SCAN1). [provided by RefSeq, Aug 2016]

TDP1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PM1

In a mutagenesis_site 3000-fold reduction in activity; abolishes hydrolysis of the covalent intermediate between the active site nucleophile and DNA. (size 0) in uniprot entity TYDP1_HUMAN

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.993

PP5

Variant 14-89993420-A-G is Pathogenic according to our data. Variant chr14-89993420-A-G is described in ClinVar as [Pathogenic]. Clinvar id is 3424.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TDP1	NM_018319.4 link	c.1478A>G	p.His493Arg	missense_variant	Exon 14 of 17	ENST00000335725.9	NP_060789.2	Q9NUW8-1A0A024R6L5B3KN41

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TDP1	ENST00000335725.9 link	c.1478A>G	p.His493Arg	missense_variant	Exon 14 of 17	1	NM_018319.4	ENSP00000337353.4		Q9NUW8-1

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152232

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000684

AC:

AN:

1461598

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727112

show subpopulations

Gnomad4 AFR exome

AF:

0.000209

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152232

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74376

show subpopulations

Gnomad4 AFR

AF:

0.0000724

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000756

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Spinocerebellar ataxia, autosomal recessive, with axonal neuropathy 1

Pathogenic:5

Nov 06, 2019

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was determined to be pathogenic according to ACMG Guidelines, 2015 [PMID:25741868]. -

Sep 22, 2024

Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 01, 2002

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Feb 10, 2025

Neurogenomics Lab, Neuroscience Institute, University Of Cape Town

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

The highest allele frequency in gnomAD v4.0 is 0.0001335 (10/74916 alleles) in African/African American population). PP3_Strong: REVEL score is 0.95. PS3_Supporting: functional studies provide supportive evidence that the variant has a damaging effect on the gene or gene product (PMID:15920477,16141202). PS4 Met: this variant has been observed in >10 probands with consistent phenotype for disorder. Sequencing funded by the International Centre for Genomic Medicine in Neuromuscular Diseases (ICGNMD): https://www.ucl.ac.uk/genomic-medicine-neuromuscular-diseases/. -

Apr 20, 2023

Johns Hopkins Genomics, Johns Hopkins University

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This TDP1 variant (rs119467003) is absent from a large population dataset and has been reported in ClinVar. The histidine residue at this position is strongly conserved across the vertebrate species assessed. This amino acid substitution (p.His493Arg) changes a key active site residue that serves as a proton donor/acceptor. Functional studies demonstrate that this variant creates a TDP1-DNA covalent intermediate that results in reduced protein activity and altered protein function. This same variant has been detected in a homozygous state in three independent families with SCAN1. We consider c.1478A>G (p.His493Arg) to be pathogenic for autosomal recessive spinocerebellar ataxia with axonal neuropathy-1 (SCAN1). -

not provided

Pathogenic:1

Aug 23, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Published functional studies demonstrate that this variant creates a TDP1-DNA complex that results in reduced protein activity and altered protein function (Interthal et al., 2005a, Interthal et al. 2005b, Hirano et al. 2007); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 21463258, 21246735, 21167187, 22536944, 19883083, 22788692, 25024006, 25111769, 31723605, 24856239, 26601161, 17948061, 19139070, 22214184, 22522093, 23626666, 25841101, 29898404, 16141202, 19211312, 19476377, 21677033, 22155078, 24637157, 16935573, 19139134, 20687496, 20097655, 33425909, 15744309, 24236237, 31429931, 12244316, 31182267, 15920477) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

1.0

BayesDel_addAF

Pathogenic

0.54

BayesDel_noAF

Pathogenic

0.54

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.67

.;D;D;.

Eigen

Pathogenic

0.85

Eigen_PC

Pathogenic

0.76

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.96

D;.;D;D

M_CAP

Pathogenic

0.49

MetaRNN

Pathogenic

0.99

D;D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

4.2

.;H;H;.

PrimateAI

Uncertain

0.72

PROVEAN

Pathogenic

-7.5

D;D;D;D

REVEL

Pathogenic

0.95

Sift

Pathogenic

0.0

D;D;D;D

Sift4G

Pathogenic

0.0

D;D;D;D

Polyphen

1.0

D;D;D;D

Vest4

0.99

MutPred

0.98

Gain of MoRF binding (P = 0.0149);Gain of MoRF binding (P = 0.0149);Gain of MoRF binding (P = 0.0149);Gain of MoRF binding (P = 0.0149);

MVP

1.0

MPC

0.60

ClinPred

1.0

GERP RS

4.6

Varity_R

0.97

gMVP

0.97

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