rs1057516995

chr17-3494446-A-Cchr17-3494446-A-Gchr17-3494446-A-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PM5 PP3_Strong

The NM_000049.4(ASPA):c.731A>C(p.His244Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H244L) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ASPA NM_000049.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: 8.51

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-3494446-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 371086.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.989

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ASPA	NM_000049.4	c.731A>C	p.His244Pro	missense_variant	5/6	ENST00000263080.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ASPA	ENST00000263080.3	c.731A>C	p.His244Pro	missense_variant	5/6	1	NM_000049.4	P1
ASPA	ENST00000456349.6	c.731A>C	p.His244Pro	missense_variant	6/7	1		P1
SPATA22	ENST00000541913.5	c.-74+18966T>G		intron_variant		2
SPATA22	ENST00000570318.1	c.-74+19165T>G		intron_variant		2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, single submitter

Submissions by phenotype

Spongy degeneration of central nervous system Uncertain:2

Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Nov 03, 2022	This sequence change replaces histidine, which is basic and polar, with proline, which is neutral and non-polar, at codon 244 of the ASPA protein (p.His244Pro). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with ASPA-related conditions. ClinVar contains an entry for this variant (Variation ID: 849366). 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. This variant disrupts the p.His244 amino acid residue in ASPA. Other variant(s) that disrupt this residue have been observed in individuals with ASPA-related conditions (PMID: 12638939, 16854607), which suggests that this may be a clinically significant amino acid residue. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.42
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
Cadd	Pathogenic	27
Dann	Benign	0.96
DEOGEN2	Pathogenic	0.97	D;D
Eigen	Pathogenic	0.83
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Pathogenic	0.30	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.4	M;M
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.53	T
PROVEAN	Pathogenic	-9.7	D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;D
Vest4		0.95
MutPred		0.87		Gain of catalytic residue at H244 (P = 0.0173);Gain of catalytic residue at H244 (P = 0.0173);
MVP		0.99
MPC		0.51
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.96
gMVP		0.99

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

Other links and lift over

dbSNP: rs1057516995; hg19: chr17-3397740;