Is ARSA p.Ala333Asp (c.998C>A) pathogenic?

ARSA p.Ala333Asp (c.998C>A) is classified Uncertain significance in ARSA (ClinVar, Single submitter, 1 submitter; last evaluated 2026-09-17). Absent from gnomAD v4.1; Associated with metachromatic leukodystrophy.

What condition is associated with ARSA p.Ala333Asp (c.998C>A)?

ARSA p.Ala333Asp (c.998C>A) is associated with metachromatic leukodystrophy (ClinVar).

How common is ARSA p.Ala333Asp (c.998C>A) in the general population?

ARSA p.Ala333Asp (c.998C>A) is absent from gnomAD v4.1 (gnomAD).

How is Metachromatic leukodystrophy inherited?

Typically Autosomal recessive (Orphanet). A genetic counselor can assess individual risk for a family.

ARSA p.Ala333Asp

c.998C>A · VCV4850948

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Not reported

no allele count reported in gnomAD v4.1 (AN 1,591,016)

Conditions

metachromatic leukodystrophy

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
REVEL	0.945	strongly pathogenic-leaning
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 9.7	GERP 2.2, phastCons 1
Regional constraint	o/e 1.00	unconstrained · MANE · 2,631 bp · p 0.96 · regional, not allelic
Overall
CADD	27.8	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

No allele count reported in gnomAD v4.1 (AN 1,591,016). This is missing data, not an absence: the variant may or may not be present in gnomAD. Rarity (ACMG PM2) and BA1/BS1 cannot be assessed for it.

Variant & gene context

Gene: ARSA
Protein: p.Ala333Asp
Coding: c.998C>A
MANE Select: NM_000487
Type: single nucleotide variant
Location: chr22:50626045 (GRCh38)
Gene constraint: LOEUF 1.166 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 96.43 · 10 PDB
Residue 333: an α-helix; a disulfide bond

Full ARSA gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

metachromatic leukodystrophy — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Metachromatic leukodystrophy (Orphanet):

Inheritance: Autosomal recessive
Onset: Adolescent, Adult, Childhood, Infancy
Prevalence: 1-9 / 100 000 (Europe)

Similar variants

ARSA p.Ala333= Likely benign ★ same residue
ARSA c.1107+1G>A Pathogenic/Likely pathogenic ★★ same condition
ARSA c.1107+1G>T Pathogenic ★★ same condition
ARSA c.1108-2A>G Pathogenic ★★ same condition
ARSA c.1108-3C>G Pathogenic/Likely pathogenic ★★ same condition
ARSA c.1210+1G>A Pathogenic ★★ same condition
ARSA c.224+1G>A Likely pathogenic ★★ same condition
ARSA c.225-1G>C Likely pathogenic ★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/arsa-p-ala333asp (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown