rs774323189

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong

The NM_000049.4(ASPA):c.859G>A(p.Ala287Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000929 in 1,614,016 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A287V) has been classified as Likely pathogenic.

Frequency

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

Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

ASPA
NM_000049.4 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 7.74

Variant links:

Genes affected

ASPA (HGNC:756): (aspartoacylase) This gene encodes an enzyme that catalyzes the conversion of N-acetyl_L-aspartic acid (NAA) to aspartate and acetate. NAA is abundant in the brain where hydrolysis by aspartoacylase is thought to help maintain white matter. This protein is an NAA scavenger in other tissues. Mutations in this gene cause Canavan disease. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Jul 2008]

ASPA links:

SPATA22 (HGNC:30705): (spermatogenesis associated 22) Predicted to be involved in regulation of meiotic cell cycle. Predicted to act upstream of or within several processes, including fertilization; gamete generation; and meiosis I cell cycle process. Predicted to be located in chromosome. [provided by Alliance of Genome Resources, Apr 2022]

SPATA22 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PM1

In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 2 uncertain in NM_000049.4

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr17-3499006-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2907869.Status of the report is criteria_provided_single_submitter, 1 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.992

PP5

Variant 17-3499005-G-A is Pathogenic according to our data. Variant chr17-3499005-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 188803.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-3499005-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ASPA	NM_000049.4 linkuse as main transcript	c.859G>A	p.Ala287Thr	missense_variant	6/6	ENST00000263080.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris
ASPA	ENST00000263080.3 linkuse as main transcript	c.859G>A	p.Ala287Thr	missense_variant	6/6	1	NM_000049.4	P1
ASPA	ENST00000456349.6 linkuse as main transcript	c.859G>A	p.Ala287Thr	missense_variant	7/7	1		P1
SPATA22	ENST00000541913.5 linkuse as main transcript	c.-74+14407C>T		intron_variant		2
SPATA22	ENST00000570318.1 linkuse as main transcript	c.-74+14606C>T		intron_variant		2

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152180

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251342

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135848

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

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:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000821

AC:

AN:

1461836

Hom.:

Cov.:

AF XY:

0.00000825

AC XY:

AN XY:

727210

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000224

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:

0.00000809

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152180

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74338

show subpopulations

Gnomad4 AFR

AF:

0.0000483

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Spongy degeneration of central nervous system

Pathogenic:5

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Nov 09, 2023	This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 287 of the ASPA protein (p.Ala287Thr). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with Canavan disease (PMID: 12638939, 16854607, 26992473). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 188803). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt ASPA protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Mar 17, 2017	- -
Likely pathogenic, criteria provided, single submitter	literature only	Counsyl	May 24, 2014	- -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Jun 01, 2022

- -

Canavan Disease, Familial Form

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Aug 04, 2016

Variant summary: The ASPA c.859G>A (p.Ala287Thr) variant involves the alteration of a conserved nucleotide. 4/4 in silico tools predict a damaging outcome for this variant (SNPs&GO not captured due to low reliability index). The C-domain of the protein forms a pocket that accommodates the acetyl group of NAA and puts severe restriction on the size of this portion of substrate. The tight pocket is formed by residues Thr-118, Gln-184, Phe-282, Glu-285, Ala-287, and Tyr-288. Thus, p.Ala287Thr is predicted to alter the hydrogen bonding network, which may lead to destabilization of interaction between the N- and C-domain (PMID: 17194761). This variant was found in 3/120632 control chromosomes at a frequency of 0.0000249, which does not exceed the estimated maximal expected allele frequency of a pathogenic ASPA variant (0.0079057). ASPA c.859G>A has been reported in numerous patients with Canavan disease. In addition, one clinical diagnostic laboratory classified this variant as likely pathogenic. Taken together, this variant is classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.77

BayesDel_addAF

Pathogenic

0.54

BayesDel_noAF

Pathogenic

0.53

Cadd

Uncertain

Dann

Uncertain

1.0

DEOGEN2

Pathogenic

0.99

D;D

Eigen

Uncertain

0.33

Eigen_PC

Benign

0.18

FATHMM_MKL

Pathogenic

0.97

M_CAP

Pathogenic

0.30

MetaRNN

Pathogenic

0.99

D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.4

M;M

MutationTaster

Benign

1.0

D;D;D

PrimateAI

Uncertain

0.59

PROVEAN

Uncertain

-3.5

D;D

REVEL

Pathogenic

0.89

Sift

Uncertain

0.0020

D;D

Sift4G

Uncertain

0.0050

D;D

Polyphen

1.0

D;D

Vest4

0.93

MutPred

0.92

Gain of glycosylation at A287 (P = 0.1084);Gain of glycosylation at A287 (P = 0.1084);

MVP

0.98

MPC

0.27

ClinPred

0.97

GERP RS

3.7

Varity_R

0.76

gMVP

0.90

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