rs904293109

Variant names:

• chr9-32973654-T-C
• rs904293109
• ENST00000468275:c.*30A>G

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_001195248.2(APTX):​c.875-2A>G variant causes a splice acceptor, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: APTX NM_001195248.2 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 6.69

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease,
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 9-32973654-T-C is Pathogenic according to our data. Variant chr9-32973654-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 434253.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr9-32973654-T-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
APTX	NM_001195248.2	c.875-2A>G		splice_acceptor_variant, intron_variant	Intron 7 of 7	ENST00000379817.7	NP_001182177.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
APTX	ENST00000379817.7	c.875-2A>G		splice_acceptor_variant, intron_variant	Intron 7 of 7	1	NM_001195248.2	ENSP00000369145.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Ataxia, early-onset, with oculomotor apraxia and hypoalbuminemia Pathogenic:2

Nov 23, 2015

Genetic Services Laboratory, University of Chicago

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

-

Neuberg Centre For Genomic Medicine, NCGM

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The observed invariant splice acceptor c.875-2A>G variant in APTX gene has been reported previously in compound heterozygous state in individual(s) affected with early-onset ataxia with oculomotor apraxia and hypoalbuminemia (Sun M, et al., 2019). The c.875-2A>G variant is absent in gnomAD Exomes. This variant has been submitted to the ClinVar database as Pathogenic. Loss of function variants have been previously reported to be disease causing. However, additional functional studies will be required to prove the pathogenicity of this variant. For these reasons, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Uncertain	0.020
CADD	Pathogenic	32
DANN	Uncertain	0.98
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Pathogenic	0.99	D
GERP RS		4.3

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.92
SpliceAI score (max)		0.41		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.41		Position offset: 29

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

Publications

LitVar

Other links and lift over

dbSNP: rs904293109; hg19: chr9-32973652;