CIAO2A

Chr 15

cytosolic iron-sulfur assembly component 2A

Also known as: CIA2A, FAM96A

NCBI Gene: 84191 ENSG00000166797 UniProt: Q9H5X1 OMIM: 618382

Predicted to enable metal ion binding activity. Involved in iron-sulfur cluster assembly and protein maturation. Located in cytosol and nucleoplasm. Part of cytosolic [4Fe-4S] assembly targeting complex. [provided by Alliance of Genome Resources, Jun 2026]

OMIM Research

OMIM ResearchGenerating clinical summary…

Active trials

Pubs (1 yr)

—

P/LP submissions

—

P/LP missense

1.46

LOEUF

Mechanism· predicted

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

LoF Constraint?

1.46LOEUF

pLI 0.000

Z-score 0.53

OE 0.82 (0.48–1.46)

Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?

0.02Z-score

OE missense 0.99 (0.83–1.19)

85 obs / 85.4 exp

Tolerant

Mild missense constraint

Observed / Expected Ratios?

LoF OE?0.82 (0.48–1.46)

0≤0.351.4

Missense OE?0.99 (0.83–1.19)

0≤0.61.4

Synonymous OE?1.20

0≤1.21.6

LoF obs/exp: 8 / 9.8Missense obs/exp: 85 / 85.4Syn Z: -0.89

Background carrier burden — how many people carry a rare variant somewhere in CIAO2A?

gnomAD v4 · ~731k individuals · PASS only

Rare means allele frequency under

Rare missense

1 in 310

205 rare PASS variants

Rare truncating (LoF)

1 in 5,000

31 rare PASS variants

Rare synonymous (reference)

1 in 590

78 rare PASS variants

Truncating variants are far rarer here than missense — that gap, in human units, is what constraint means for CIAO2A. A background rate for each class, not the frequency of any particular variant; thin-coverage exons undercount.

By genetic ancestry · 9 gnomAD groups · rare = under 0.1% in that group

Group	People	Missense	Truncating
European (non-Finnish)	~556k	1 in 320	1 in 4,300
South Asian	~43k	1 in 440	1 in 8,400
Remaining (unassigned)	~30k	1 in 260	≈ 1 in 15,000
European (Finnish)	~27k	1 in 2,200	≈ 1 in 27,000
Admixed American	~22k	1 in 450	1 in 1,700
African / African American	~21k	1 in 320	≈ 1 in 5,600
East Asian	~20k	1 in 660	1 in 2,800
Ashkenazi Jewish	~13k	≈ 1 in 4,400	none seen
Middle Eastern	~2,884	1 in 260	≈ 1 in 2,700

Each group is summed over the variants that are rare in that group. Grey ≈ figures rest on fewer than five expected carriers — too few to distinguish groups. Differences mostly reflect how many people were sampled and how much variation each ancestry carries, not disease risk.

Exome coverage (gnomAD): 4 of 5 coding exons well covered in gnomAD exomes; exon 4 marginal. Genomes: all 5.? see exons ↓