chr17-3498984-C-T

Variant names:

• chr17-3498984-C-T
• rs750505963
• NM_000049.4:c.838C>T

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1 PM2 PP2 PP3_Strong PP5_Very_Strong

The NM_000049.4(ASPA):​c.838C>T​(p.Pro280Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000157 in 1,461,858 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. P280L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000016 (0 hom.)
• Consequence: ASPA NM_000049.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2 U:1
• Conservation: PhyloP100: 7.56
• Publications: 2 publications found

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]

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 Gene-Disease associations (from GenCC):

• infertility disorder

  Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics

ACMG classification

Our verdict: Pathogenic. The variant received 17 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 6 uncertain in NM_000049.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 48 curated pathogenic missense variants (we use a threshold of 10). The gene has 6 curated benign missense variants. Gene score misZ: 0.47868 (below the threshold of 3.09). Trascript score misZ: 1.2423 (below the threshold of 3.09). GenCC associations: The gene is linked to Canavan disease, mild Canavan disease, severe Canavan disease.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.99
• PP5: Variant 17-3498984-C-T is Pathogenic according to our data. Variant chr17-3498984-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 554736.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
ASPA	NM_000049.4	c.838C>T	p.Pro280Ser	missense_variant	Exon 6 of 6	ENST00000263080.3	NP_000040.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ASPA	ENST00000263080.3	c.838C>T	p.Pro280Ser	missense_variant	Exon 6 of 6	1	NM_000049.4	ENSP00000263080.2
ASPA	ENST00000456349.6	c.838C>T	p.Pro280Ser	missense_variant	Exon 7 of 7	1		ENSP00000409976.2
SPATA22	ENST00000541913.5	c.-74+14428G>A		intron_variant	Intron 1 of 8	2		ENSP00000441920.1
SPATA22	ENST00000570318.1	c.-74+14627G>A		intron_variant	Intron 1 of 1	2		ENSP00000459147.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.0000119 AC: 3 AN: 251412 AF XY: 0.0000147

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000157 AC: 23 AN: 1461858 Hom.: 0 Cov.: 30 AF XY: 0.0000151 AC XY: 11 AN XY: 727234

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.0000224 AC: 1 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000198 AC: 22 AN: 1111986

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000218 Hom.: 0

Bravo AF: 0.00000756

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Spongy degeneration of central nervous system Pathogenic:2 Uncertain:1

Feb 13, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces proline, which is neutral and non-polar, with serine, which is neutral and polar, at codon 280 of the ASPA protein (p.Pro280Ser). This variant is present in population databases (rs750505963, gnomAD 0.003%). This missense change has been observed in individual(s) with clinical features of Canavan disease (PMID: 10407784; Invitae). 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: 554736). 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. -

Mar 04, 2024

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 02, 2017

Counsyl

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.62
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.55
CADD	Uncertain	24
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.99	D;D
Eigen	Pathogenic	0.79
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.91	.;D
M_CAP	Pathogenic	0.32	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.1	M;M
PhyloP100		7.6
PrimateAI	Uncertain	0.63	T
PROVEAN	Pathogenic	-7.6	D;D
REVEL	Pathogenic	0.92
Sift	Pathogenic	0.0	D;D
Sift4G	Uncertain	0.041	D;D
Polyphen		1.0	D;D
Vest4		0.94
MutPred		0.90		Gain of catalytic residue at P280 (P = 0.187);Gain of catalytic residue at P280 (P = 0.187);
MVP		0.98
MPC		0.42
ClinPred		1.0	D
GERP RS		5.8
Varity_R		0.92
gMVP		0.92
Mutation Taster		=7/93	disease causing

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

Other links and lift over

dbSNP: rs750505963; hg19: chr17-3402278;