dbSNP rs201912053: APTX:p.Arg42* (chr9-32989768-G-A) – ACMG Classification: Pathogenic (14 pts)

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong

The NM_001369002.1(APTX):c.-136C>T variant causes a 5 prime UTR premature start codon gain 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 (★★).

Frequency

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

Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

APTX
NM_001369002.1 5_prime_UTR_premature_start_codon_gain

Scores

Clinical Significance

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

Conservation

PhyloP100: 3.14

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 links:

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

BayesDel_addAF computational evidence supports a deleterious effect, 0.503

PP5

Variant 9-32989768-G-A is Pathogenic according to our data. Variant chr9-32989768-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id 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
APTX	NM_001195248.2 link	c.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
APTX	ENST00000379817.7 link	c.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:

AN:

152188

Hom.:

Cov.:

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

GnomAD3 exomes

AF:

0.0000437

AC:

AN:

251442

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135896

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 SAS 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:

AN:

1461880

Hom.:

Cov.:

AF XY:

0.0000275

AC XY:

AN XY:

727244

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000447

Gnomad4 ASJ exome

AF:

0.000612

Gnomad4 EAS exome

AF:

0.0000504

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000171

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152188

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74342

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.000288

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

Alfa

AF:

0.000113

Hom.:

Bravo

AF:

0.0000302

ExAC

AF:

0.0000247

AC:

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 -

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

- -

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). -

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. -

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

BayesDel_noAF

Pathogenic

0.54

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Pathogenic

0.83

Eigen_PC

Pathogenic

0.71

FATHMM_MKL

Uncertain

0.94

Vest4

0.90

GERP RS

5.3

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

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