Is ARSB p.Ser403Leu (c.1208C>T) pathogenic?

ARSB p.Ser403Leu (c.1208C>T) is classified Uncertain significance in ARSB (ClinVar, Multiple submitters, 2 submitters; last evaluated 2021-10-27). AlphaMissense: likely benign (0.0999); Very rare (popmax 0.00988%, sas); Associated with mucopolysaccharidosis type 6.

What condition is associated with ARSB p.Ser403Leu (c.1208C>T)?

ARSB p.Ser403Leu (c.1208C>T) is associated with mucopolysaccharidosis type 6 (ClinVar).

How common is ARSB p.Ser403Leu (c.1208C>T) in the general population?

ARSB p.Ser403Leu (c.1208C>T) is very rare (popmax 0.00988%, sas) (gnomAD).

How is Mucopolysaccharidosis type 6 inherited?

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

What do computational predictors say about ARSB p.Ser403Leu (c.1208C>T)?

AlphaMissense predicts likely benign (score 0.0999) — an in-silico prediction, not a clinical call.

ARSB p.Ser403Leu

c.1208C>T · rs771296632 · VCV2159622

Uncertain significance Multiple submitters

Classification

Uncertain significance

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

AlphaMissense

likely benign

0.0999 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00988%, sas)

Missense predictors

0/2 damaging

AlphaMissense, SaProt · REVEL no call

Conditions

mucopolysaccharidosis type 6

Computational evidence

Protein change
AlphaMissense	0.0999	likely benign
REVEL	0.411	indeterminate
SaProt	LLR -6.11	tolerated
⇒ AlphaMissense and SaProt both call this tolerated; REVEL makes no call.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 9.9	GERP 1.8, phastCons 1
Overall
CADD	17.24	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean tolerated — a triage signal, not a reclassification

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00988% South Asian · 9/91,074 alleles

Filtering AF 0.00514% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00375%

Overall 0.0013% 19/1,461,344 alleles · very rare

Ancestry group	Frequency	1 in
South Asiangrpmax	0.00988%	10,119
European (non-Finnish)	0.000848%	117,964

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: ARSB
Protein: p.Ser403Leu
Coding: c.1208C>T
MANE Select: NM_020427 · reported on NM_000046
dbSNP: rs771296632
Type: single nucleotide variant
Location: chr5:78839361 (GRCh38)
Structure: AlphaFold pLDDT 84.32 · 2 PDB

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

Disease context

mucopolysaccharidosis type 6 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Mucopolysaccharidosis type 6 (Orphanet):

Inheritance: Autosomal recessive
Onset: Childhood
Prevalence: 1-9 / 1 000 000 (Europe)

Similar variants

ARSB p.Ser403Ter Pathogenic ★ same residue
ARSB p.Ser403= Likely benign ★ same residue
ARSB p.Ser403fs Pathogenic ★ same residue
ARSB c.1142+1G>A Pathogenic ★★ same condition
ARSB c.1142+1G>T Pathogenic ★★ same condition
ARSB c.1142+2T>A Pathogenic/Likely pathogenic ★★ same condition
ARSB c.1142+2T>C Pathogenic ★★ same condition
ARSB c.1143-1G>A Pathogenic/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/arsb-p-ser403leu (accessed [today's date]).

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