ARSA

Chr 22AR

arylsulfatase A

Also known as: ASA, MLD

NCBI Gene: 410 ENSG00000100299 UniProt: O43681 OMIM: 607574

The protein hydrolyzes cerebroside sulfate to cerebroside and sulfate, functioning as a lysosomal enzyme essential for sulfatide metabolism. Mutations cause metachromatic leukodystrophy, a progressive demyelinating disease that presents with neurological deterioration and is ultimately fatal. This condition follows autosomal recessive inheritance.

GeneReviews OMIM ResearchSummary from RefSeq, OMIM, UniProt

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]

GeneReviews OMIM ResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

Metachromatic leukodystrophyMIM #250100

UniProtCardiomyopathy, dilated, 2H

Clinical highlights

Management implications

ARSA has an approved disease-modifying therapy

Gene-disease validity (ClinGen)

metachromatic leukodystrophy · ARDefinitivesufficient evidence for diagnostic panels

Interpreting a novel variant

Loss of function is the curated mechanism (Gene2Phenotype), though the gene is not strongly LoF-constrained in the population — weigh truncating variants against that tolerance.Curated gene-level mechanism — a prior for triage, not a per-variant call.

Active trials

119

Pubs (1 yr)

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P/LP submissions

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P/LP missense

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LOEUF

LOF

Mechanism· G2P

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GeneReview available — ARSA

Authoritative clinical overview · Recommended first read

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Some data sources returned errors (1)

gnomad: TimeoutError: The operation was aborted due to timeout

atidarsagene autotemcel (Lenmeldy)
ex-vivo gene therapyApproved · FDA 2024
Autologous CD34+ HSCs transduced with an ARSA lentivirus.
Delivery: One-time IV after myeloablative conditioningEligibility: Pre-/early-symptomatic late-infantile or early-juvenile MLD

Therapeutic landscape as of 2026-07. Educational only. Investigational ≠ available; not medical advice or eligibility. Approved entries are precise; investigational program names/phases are conservative and move fast. Curated from FDA/EMA approvals and the clinical-trial literature; verify against current labeling + ClinicalTrials.gov.

ClinicalTrials.gov