rs199476342

Variant names:

• chr22-50626594-T-C
• rs199476342
• NM_000487.6:c.851A>G

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM2 PP3_Moderate PP5_Very_Strong

The NM_000487.6(ARSA):​c.851A>G​(p.Asn284Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,460,844 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 (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: ARSA NM_000487.6 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3 O:2
• Conservation: PhyloP100: 2.66

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.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 22-50626594-T-C is Pathogenic according to our data. Variant chr22-50626594-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 68152.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr22-50626594-T-C is described in Lovd as [Pathogenic]. Variant chr22-50626594-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ARSA	NM_000487.6	c.851A>G	p.Asn284Ser	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.851A>G	p.Asn284Ser	missense_variant	Exon 4 of 8	1	NM_000487.6	ENSP00000216124.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1460844 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 726714

Gnomad4 AFR exome AF: 0.0000299

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

Bravo AF: 0.0000113

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3 Other:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Metachromatic leukodystrophy Pathogenic:3 Other:1

Nov 02, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces asparagine, which is neutral and polar, with serine, which is neutral and polar, at codon 284 of the ARSA protein (p.Asn284Ser). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with metachromatic leukodystrophy (PMID: 33185815). This variant is also known as c.845A>G (p.Asn282Ser). ClinVar contains an entry for this variant (Variation ID: 68152). 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 ARSA protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects ARSA function (PMID: 18693274). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. For these reasons, this variant has been classified as Pathogenic. -

Aug 14, 2024

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: ARSA c.851A>G (p.Asn284Ser) results in a conservative amino acid change in the encoded protein sequence. Two of four in-silico tools predict a benign effect of the variant on protein function. The frequency data for this variant in gnomAD is considered unreliable, as metrics indicate poor data quality at this position. c.851A>G has been reported in the literature in multiple individuals affected with Metachromatic Leukodystrophy (e.g. Grossi_2008, Amr_2021). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function, finding that the variant resulted in <1% of wild type ARSA activity (Grossi_2008). The following publications have been ascertained in the context of this evaluation (PMID: 18693274, 33185815). ClinVar contains an entry for this variant (Variation ID: 68152). Based on the evidence outlined above, the variant was classified as pathogenic. -

-

Gelb Laboratory, University of Washington

Significance: not provided

Review Status: no classification provided

Collection Method: in vitro

- -

Sep 01, 2022

3billion

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is not observed in the gnomAD v2.1.1 dataset. Missense changes are a common disease-causing mechanism. In silico tool predictions suggest damaging effect of the variant on gene or gene product (REVEL: 0.86; 3Cnet: 1.00). Same nucleotide change resulting in same amino acid change has been previously reported to be associated with ARSA -related disorder (PMID: 18693274). A different missense change at the same codon (p.Asn284Lys) has been reported to be associated with ARSA -related disorder (ClinVar ID: VCV000431089 / PMID: 28762252). Therefore, this variant is classified as Likely pathogenic according to the recommendation of ACMG/AMP guideline. -

not provided Other:1

-

UniProtKB/Swiss-Prot

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.080
CADD	Pathogenic	35
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.61	D;D;D;.;D
Eigen	Pathogenic	0.76
Eigen_PC	Uncertain	0.64
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.89	.;.;.;D;D
M_CAP	Pathogenic	0.52	D
MetaRNN	Pathogenic	0.95	D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
PrimateAI	Benign	0.47	T
PROVEAN	Pathogenic	-4.8	D;D;D;D;D
REVEL	Pathogenic	0.86
Sift	Benign	0.032	D;D;D;D;D
Sift4G	Uncertain	0.0090	D;D;D;T;D
Vest4		0.76
MVP		1.0
ClinPred		0.99	D
GERP RS		5.3
gMVP		0.97

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.95		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.95		Position offset: 1

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

Publications

LitVar

Other links and lift over

dbSNP: rs199476342; hg19: chr22-51065022;