22-50626676-C-T

Variant names:

• chr22-50626676-C-T
• rs80338819
• NM_000487.6:c.769G>A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Moderate

The NM_000487.6(ARSA):​c.769G>A​(p.Asp257Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,806 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 10/17 in silico tools predict a damaging 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. D257H) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: ARSA NM_000487.6 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1 O:1
• Conservation: PhyloP100: 7.69

Genes affected

ARSA (HGNC:713): (arylsulfatase A) The protein encoded by this gene hydrolyzes cerebroside sulfate to cerebroside and sulfate. Defects in this gene lead to metachromatic leucodystrophy (MLD), a progressive demyelination disease which results in a variety of neurological symptoms and ultimately death. Alternatively spliced transcript variants have been described for this gene. [provided by RefSeq, Dec 2010]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PM1: In a helix (size 22) in uniprot entity ARSA_HUMAN there are 18 pathogenic changes around while only 0 benign (100%) in NM_000487.6
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr22-50626676-C-G is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.967
• PP5: Variant 22-50626676-C-T is Pathogenic according to our data. Variant chr22-50626676-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2999447.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ARSA	NM_000487.6	c.769G>A	p.Asp257Asn	missense_variant	Exon 4 of 8	ENST00000216124.10	NP_000478.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ARSA	ENST00000216124.10	c.769G>A	p.Asp257Asn	missense_variant	Exon 4 of 8	1	NM_000487.6	ENSP00000216124.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000797 AC: 2 AN: 251058 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135822

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: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461806 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727200

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Metachromatic leukodystrophy Pathogenic:1 Other:1

-

Gelb Laboratory, University of Washington

Significance: not provided

Review Status: no classification provided

Collection Method: in vitro

- -

Oct 23, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with asparagine, which is neutral and polar, at codon 257 of the ARSA protein (p.Asp257Asn). This variant is present in population databases (rs80338819, gnomAD 0.002%). This variant has not been reported in the literature in individuals affected with ARSA-related conditions. Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt ARSA protein function with a positive predictive value of 95%. This variant disrupts the p.Asp257 amino acid residue in ARSA. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 8982952, 10477432, 12445909, 15720392). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.16
CADD	Pathogenic	30
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.66	D;D;D;.;D
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.88	.;.;.;D;D
M_CAP	Pathogenic	0.64	D
MetaRNN	Pathogenic	0.97	D;D;D;D;D
MetaSVM	Pathogenic	0.94	D
PrimateAI	Uncertain	0.64	T
PROVEAN	Pathogenic	-4.7	D;D;D;D;D
REVEL	Pathogenic	0.87
Sift	Pathogenic	0.0	D;D;D;D;D
Sift4G	Uncertain	0.015	D;D;D;D;D
Vest4		0.89
MVP		1.0
ClinPred		1.0	D
GERP RS		5.4
gMVP		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs80338819; hg19: chr22-51065104;