rs786204673

Positions:

• chr22-50627326-AG-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000487.6(ARSA):​c.304delC​(p.Leu102fs) variant causes a frameshift change. The variant allele was found at a frequency of 0.0000132 in 1,437,858 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000013 (0 hom.)
• Consequence: ARSA NM_000487.6 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 3.92

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]

ARSA (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 22-50627326-AG-A is Pathogenic according to our data. Variant chr22-50627326-AG-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 189073.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr22-50627326-AG-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ARSA	NM_000487.6	c.304delC	p.Leu102fs	frameshift_variant	2/8	ENST00000216124.10	NP_000478.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ARSA	ENST00000216124.10	c.304delC	p.Leu102fs	frameshift_variant	2/8	1	NM_000487.6	ENSP00000216124.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.0000132 AC: 19 AN: 1437858 Hom.: 0 Cov.: 33 AF XY: 0.0000126 AC XY: 9 AN XY: 713604

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: 0.0000172

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Metachromatic leukodystrophy Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 19, 2023	This sequence change creates a premature translational stop signal (p.Leu102Cysfs*6) in the ARSA gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in ARSA are known to be pathogenic (PMID: 8962139, 10477432). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with metachromatic leukodystrophy (PMID: 8101038). ClinVar contains an entry for this variant (Variation ID: 189073). 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	Dec 26, 2017	Variant summary: The ARSA c.304delC (p.Leu102CysfsX6) variant results in a premature termination codon, predicted to cause a truncated or absent ARSA protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory (e.g. c.960G>A/Trp320X). One in silico tool predicts a damaging outcome for this variant. This variant is absent in 190968 control chromosomes. It has been reported in at least one late-infantile metachromatic leukodystrophy patient as a compound heterozygote, and this patient had a residual arylsulfatase A (ARSA) activity <10% of WT level (Kreysing_1993). In addition, one other clinical diagnostic laboratory classified this variant as likely pathogenic. Taken together, this variant is classified as pathogenic. -
Likely pathogenic, criteria provided, single submitter	literature only	Counsyl	Nov 26, 2014	- -

Metachromatic leukodystrophy, late infantile form Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Aug 01, 1993

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Mar 27, 2024

Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 32875726, 8101038) -

Computational scores

Source: dbNSFP v4.3

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: rs786204673; hg19: chr22-51065754;