SUOX

Chr 12

sulfite oxidase

Also known as: HSO

NCBI Gene: 6821 ENSG00000139531 UniProt: P51687

Sulfite oxidase is a mitochondrial enzyme that catalyzes the oxidation of sulfite to sulfate, representing the final step in the degradation of sulfur-containing amino acids cysteine and methionine. Biallelic mutations cause sulfite oxidase deficiency, an autosomal recessive disorder characterized by severe neurological abnormalities that are often fatal in early childhood. The gene shows tolerance to loss-of-function variants (pLI near zero), consistent with its recessive inheritance pattern.

GeneReviews ResearchSummary from RefSeq, OMIM, UniProt

Sulfite oxidase is a homodimeric protein localized to the intermembrane space of mitochondria. Each subunit contains a heme domain and a molybdopterin-binding domain. The enzyme catalyzes the oxidation of sulfite to sulfate, the final reaction in the oxidative degradation of the sulfur amino acids cysteine and methionine. Sulfite oxidase deficiency results in neurological abnormalities which are often fatal at an early age. Alternative splicing results in multiple transcript variants encoding identical proteins. [provided by RefSeq, Jul 2008]

GeneReviews ResearchGenerating clinical summary…

LOFmechanismLOEUF 1.08

Clinical Summary— SUOX

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Gene-Disease Validity (ClinGen)

isolated sulfite oxidase deficiency · ARDefinitive

Definitive — sufficient evidence for diagnostic panels

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Population Constraint (gnomAD)

Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

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ClinVar Variants

83 unique Pathogenic / Likely Pathogenic· 203 VUS of 519 total submissions

Explore recent and relevant literature in Research Assistant →

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GeneReview available — SUOX

Authoritative clinical overview · Recommended first read

Open GeneReview ↗

Some data sources returned errors (1)

omim: Error: OMIM fetch failed: 429

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

LoF Constraint?

1.08LOEUF

pLI 0.000

Z-score 1.31

OE 0.67 (0.43–1.08)

Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?

0.45Z-score

OE missense 0.93 (0.84–1.02)

289 obs / 311.3 exp

Tolerant

Mild missense constraint

Observed / Expected Ratios?

LoF OE?0.67 (0.43–1.08)

0≤0.351.4

Missense OE?0.93 (0.84–1.02)

0≤0.61.4

Synonymous OE?0.90

0≤1.21.6

LoF obs/exp: 12 / 18.0Missense obs/exp: 289 / 311.3Syn Z: 0.85

ClinVar Variant Classifications

519 submitted variants in ClinVar

ClinVar

Classification Summary

Pathogenic55

Likely Pathogenic28

VUS203

Likely Benign199

Benign6

Conflicting24

Pathogenic

Likely Pathogenic

203

VUS

199

Likely Benign

Benign

Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

Classification	LoF	Missense + Inframe	Non-coding	Synonymous	Total
Pathogenic	51	0	4	0	55
Likely Pathogenic	14	14	0	0	28
VUS	1	183	19	0	203
Likely Benign	0	8	30	161	199
Benign	0	1	3	2	6
Conflicting	—				24
Total	66	206	56	163	515

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

6 pathogenic / likely-pathogenic (of 13) ClinVar copy-number / structural variants overlap SUOX — these span large chromosomal regions, not the gene specifically, and are excluded from the counts above. Explore in CNV tools →