rs199476382

Positions:

• chr22-50626195-C-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000487.6(ARSA):​c.938G>A​(p.Arg313Gln) variant causes a missense change. The variant allele was found at a frequency of 0.0000158 in 1,458,568 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. R313G) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.000016 (0 hom.)
• Consequence: ARSA NM_000487.6 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6 O:2
• Conservation: PhyloP100: 4.92

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 18 ACMG points.

• PM1: In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain 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 chr22-50626196-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1489713.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.978
• PP5: Variant 22-50626195-C-T is Pathogenic according to our data. Variant chr22-50626195-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 68165.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr22-50626195-C-T is described in Lovd as [Pathogenic]. Variant chr22-50626195-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ARSA	NM_000487.6	c.938G>A	p.Arg313Gln	missense_variant	5/8	ENST00000216124.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ARSA	ENST00000216124.10	c.938G>A	p.Arg313Gln	missense_variant	5/8	1	NM_000487.6	P1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD3 exomes AF: 0.00000826 AC: 2 AN: 241990 Hom.: 0 AF XY: 0.00000761 AC XY: 1 AN XY: 131324

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: 0.0000335

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000918

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000158 AC: 23 AN: 1458568 Hom.: 0 Cov.: 35 AF XY: 0.0000165 AC XY: 12 AN XY: 725368

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: 0.0000234

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000171

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 34

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6 Other:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Metachromatic leukodystrophy Pathogenic:4 Other:1

Pathogenic, criteria provided, single submitter	clinical testing	Neuberg Centre For Genomic Medicine, NCGM	-	The missense variant p.R313Q in ARSA (NM_000487.6) has been observed to be homozygous in individuals affected with metachromatic leukodystrophy (Shukla P et al; Gonorazky HD et al). Other variant(s) that disrupt this residue have been observed in individuals with ARSA-related conditions, indicating that the residue is functionally important(Cesani M et al). This variant was found in ClinVar (Variant 68165) with a classification of Pathogenic/Likely Pathogenic. The p.R313Q variant is observed in 1/29,832 (0.0034%) alleles from individuals of South Asian background in gnomAD Exomes and is novel (not in any individuals) in 1000 Genomes. In silico tools are contradictory in their predictions (SIFT-Tolerated, Polyphen- Damaging) and the residue is conserved across species. For these reasons, this variant has been classified as Pathogenic -
Likely pathogenic, no assertion criteria provided	clinical testing	Counsyl	Dec 13, 2018	- -
not provided, no classification provided	in vitro	Gelb Laboratory, University of Washington	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 08, 2024	This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 313 of the ARSA protein (p.Arg313Gln). This variant is present in population databases (rs199476382, gnomAD 0.003%). This missense change has been observed in individual(s) with metachromatic leukodystrophy (PMID: 21167507, 28667691). This variant is also known as Arg311Gln. ClinVar contains an entry for this variant (Variation ID: 68165). 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%. This variant disrupts the p.Arg313 amino acid residue in ARSA. Other variant(s) that disrupt this residue have been observed in individuals with ARSA-related conditions (PMID: 26462614), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 02, 2024	Variant summary: ARSA c.938G>A (p.Arg313Gln) results in a conservative amino acid change in the encoded protein sequence. Three of four in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8.3e-06 in 241990 control chromosomes. c.938G>A has been reported in the literature in multiple homozygous and compound heterozygous individuals affected with Metachromatic Leukodystrophy (e.g. Barth_1995, Biffi_2008, Shukla_2011, Fumagalli_2021). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no direct experimental evidence demonstrating an impact on protein function has been reported, although cells from homozygous or compound heterozygous patients showed little or no detectible ASA enzymatic activity (e.g. Biffi_2008, Shukla_2011). The following publications have been ascertained in the context of this evaluation (PMID: 21167507, 7581401, 18786133, 33855715). ClinVar contains an entry for this variant (Variation ID: 68165). Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:2 Other:1

not provided, no classification provided	literature only	UniProtKB/Swiss-Prot	-	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Aug 29, 2016	The R313Q variant in the ARSA gene, also known as R311Q using alternate nomenclature, has been reported previously in association with late-infantile metachromatic leukodystrophy in two siblings who were homozygous for R313Q (Shukla et al., 2011; Liaw et al., 2015) and in an affected individual who was heterozygous for R313Q as well as heterozygous for a second pathogenic variant in the ARSA gene (Biffi et al., 2008). The R313Q variant has also been reported in an individual with juvenile metachromatic leukodystrophy who was heterozygous for R313Q without an identified second pathogenic variant but who was also heterozygous for an ARSA pseudodeficiency allele (Barth et al., 1995). The R313Q variant was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The R313Q variant is a semi-conservative amino acid substitution, which may impact secondary protein structure as these residues differ in some properties. This substitution occurs at a position that is conserved across species. In silico analysis predicts this variant is probably damaging to the protein structure/function. A missense variant at this same residue (R313P) as well as in nearby residues (G310V, G310D, G311S, E314D, A316T, A316D) have been reported in the Human Gene Mutation Database in association with metachromatic leukodystrophy (Stenson et al., 2014), supporting the functional importance of this region of the protein. The R313Q variant is a strong candidate for a pathogenic variant, however the possibility it may be a rare benign variant cannot be excluded. -
Pathogenic, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	Jul 16, 2020	PS3, PS4_Moderate, PM2, PP4, PP3 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.53
CADD	Pathogenic	32
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.49	T;T;T;.;T
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Uncertain	0.94	D
M_CAP	Pathogenic	0.89	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
PrimateAI	Uncertain	0.53	T
PROVEAN	Uncertain	-4.0	D;D;D;D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D;D;D;D
Sift4G	Uncertain	0.0070	D;D;D;D;D
Vest4		0.99
MVP		1.0
ClinPred		1.0	D
GERP RS		5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
gMVP		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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: rs199476382; hg19: chr22-51064623; COSMIC: COSV53350354; COSMIC: COSV53350354;