rs201912053

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_001195248.2(APTX):​c.124C>T​(p.Arg42*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000285 in 1,614,068 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 Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

APTX
NM_001195248.2 stop_gained

Scores

4
2
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 3.14

Publications

2 publications found
Variant links:
Genes affected
APTX (HGNC:15984): (aprataxin) This gene encodes a member of the histidine triad (HIT) superfamily. The encoded protein may play a role in single-stranded DNA repair through its nucleotide-binding activity and its diadenosine polyphosphate hydrolase activity. Mutations in this gene have been associated with ataxia-ocular apraxia. Alternatively spliced transcript variants have been identified for this gene.[provided by RefSeq, Aug 2010]
APTX Gene-Disease associations (from GenCC):
  • ataxia, early-onset, with oculomotor apraxia and hypoalbuminemia
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 9-32989768-G-A is Pathogenic according to our data. Variant chr9-32989768-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 420789.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
APTXNM_001195248.2 linkc.124C>T p.Arg42* stop_gained Exon 2 of 8 ENST00000379817.7 NP_001182177.2 Q7Z2E3-7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
APTXENST00000379817.7 linkc.124C>T p.Arg42* stop_gained Exon 2 of 8 1 NM_001195248.2 ENSP00000369145.2 Q7Z2E3-7

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152188
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
Gnomad ASJ
AF:
0.000288
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
GnomAD2 exomes
AF:
0.0000437
AC:
11
AN:
251442
AF XY:
0.0000221
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000578
Gnomad ASJ exome
AF:
0.000694
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000294
AC:
43
AN:
1461880
Hom.:
0
Cov.:
31
AF XY:
0.0000275
AC XY:
20
AN XY:
727244
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.0000447
AC:
2
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.000612
AC:
16
AN:
26136
East Asian (EAS)
AF:
0.0000504
AC:
2
AN:
39698
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000171
AC:
19
AN:
1112012
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.472
Heterozygous variant carriers
0
4
8
11
15
19
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000197
AC:
3
AN:
152188
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74342
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41444
American (AMR)
AF:
0.0000654
AC:
1
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.000288
AC:
1
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10600
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68044
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.542
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000737
Hom.:
0
Bravo
AF:
0.0000302
ExAC
AF:
0.0000247
AC:
3

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:5
Oct 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

APTX: PVS1, PM2, PM3:Supporting -

Jul 01, 2022
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Reported as a single heterozygous variant in a newborn undergoing exome sequencing through the BabySeq Project (Ceyhan-Birsoy et al., 2019); Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 30609409) -

Jan 15, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Arg42*) in the APTX gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in APTX are known to be pathogenic (PMID: 15719174, 21465257, 23183622, 26285866). This variant is present in population databases (rs201912053, gnomAD 0.08%). This variant has not been reported in the literature in individuals affected with APTX-related conditions. ClinVar contains an entry for this variant (Variation ID: 420789). For these reasons, this variant has been classified as Pathogenic. -

Sep 14, 2023
Athena Diagnostics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is expected to result in the loss of a functional protein. The frequency of this variant in the general population is consistent with pathogenicity (http://gnomad.broadinstitute.org). -

Jun 17, 2021
Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Ataxia, early-onset, with oculomotor apraxia and hypoalbuminemia Pathogenic:1
Jan 03, 2017
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Arg42X (NM_175073.2 c.124C>T) variant in APTX has not been reported in ind ividuals with clinical features of ataxia with oculomotor apraxia type 1. This v ariant has been identified in 3/11578 of Latino chromosomes by the Exome Aggrega tion Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs201912053). This nonsense variant leads to a premature termination codon at position 42, which is predicted to lead to a truncated or absent protein. Biallelic loss of function of the APTX gene has been associated with ataxia with oculomotor apraxia type 1. In summary, although additional studies are required to fully establish a null effect on the protein, the p.Arg42X variant in APTX is likely pathogenic for ata xia with oculomotor apraxia type 1 in an autosomal recessive manner based upon p redicted impact on protein function. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.50
D
BayesDel_noAF
Pathogenic
0.54
CADD
Pathogenic
40
DANN
Uncertain
1.0
Eigen
Pathogenic
0.83
Eigen_PC
Pathogenic
0.71
FATHMM_MKL
Uncertain
0.94
D
PhyloP100
3.1
Vest4
0.90
GERP RS
5.3
Mutation Taster
=5/195
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs201912053; hg19: chr9-32989766; API