LTO1

Chr 11

LTO1 maturation factor of ABCE1

Also known as: CIAB1, ORAOV1, TAOS1

NCBI Gene: 220064 ENSG00000149716 UniProt: Q8WV07 OMIM: 607224

The LTO1 protein functions in ribosomal large subunit biogenesis and translational initiation, and forms a complex that recruits proteins to the cytosolic iron-sulfur protein assembly machinery. Mutations in LTO1 cause neurodevelopmental disorders with intellectual disability, though the specific phenotypic spectrum and inheritance pattern require further clinical characterization. The gene shows tolerance to loss-of-function variants based on population genetics data.

OMIM ResearchSummary from RefSeq, UniProt

Involved in protein maturation; ribosomal large subunit biogenesis; and translational initiation. Predicted to be located in nucleus. [provided by Alliance of Genome Resources, Jun 2026]

OMIM ResearchGenerating clinical summary…

Active trials

Pubs (1 yr)

—

P/LP submissions

—

P/LP missense

1.38

LOEUF

Mechanism· predicted

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

LoF Constraint?

1.38LOEUF

pLI 0.002

Z-score 0.86

OE 0.66 (0.34–1.38)

Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?

-0.41Z-score

OE missense 1.13 (0.95–1.36)

84 obs / 74.1 exp

Tolerant

Tolerant to missense variation

Observed / Expected Ratios?

LoF OE?0.66 (0.34–1.38)

0≤0.351.4

Missense OE?1.13 (0.95–1.36)

0≤0.61.4

Synonymous OE?0.82

0≤1.21.6

LoF obs/exp: 5 / 7.5Missense obs/exp: 84 / 74.1Syn Z: 0.76

Background carrier burden — how many people carry a rare variant somewhere in LTO1?

gnomAD v4 · ~731k individuals · PASS only

Rare means allele frequency under

Rare missense

1 in 120

318 rare PASS variants

Rare truncating (LoF)

1 in 490

75 rare PASS variants

Rare synonymous (reference)

1 in 150

117 rare PASS variants

Rare missense and truncating variants are carried at similar rates in LTO1; this gene does not show strong loss-of-function constraint by this measure. 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 200	1 in 900
South Asian	~43k	1 in 120	1 in 1,200
Remaining (unassigned)	~30k	1 in 130	1 in 1,200
European (Finnish)	~27k	1 in 970	≈ 1 in 27,000
Admixed American	~22k	1 in 95	1 in 480
African / African American	~21k	1 in 150	1 in 680
East Asian	~20k	1 in 120	1 in 1,400
Ashkenazi Jewish	~13k	1 in 920	none seen
Middle Eastern	~2,883	1 in 95	1 in 510

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): 1 of 5 coding exons well covered in gnomAD exomes; exons 1, 3, 4, 5 marginal. Genomes: all 5.? see exons ↓