FOXO3B

Chr 17

forkhead box O3B

Also known as: FKHRL1P1, ZNF286C

NCBI Gene: 2310 ENSG00000240445 UniProt: A0A2Z4LIS9 OMIM: 620471

FOXO3B encodes a transcription factor that regulates gene expression by binding to specific DNA sequences and controlling RNA polymerase II-mediated transcription. The protein is predicted to function in both the nucleus and mitochondrial matrix. No established disease associations or inheritance patterns have been reported for mutations in this gene.

OMIM ResearchSummary from RefSeq, UniProt

Predicted to enable DNA-binding transcription factor activity, RNA polymerase II-specific and RNA polymerase II cis-regulatory region sequence-specific DNA binding activity. Predicted to be involved in regulation of transcription by RNA polymerase II and response to starvation. Predicted to be located in mitochondrial matrix. Predicted to be active 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

—

LOEUF

Multiple*

Mechanism· predicted

Population Genetics & Constraint

gnomAD

Constraint data not available from gnomAD.

Background carrier burden — how many people carry a rare variant somewhere in FOXO3B?

gnomAD v4 · ~731k individuals · PASS only

Rare means allele frequency under

Rare missense

1 in 79

369 rare PASS variants

Rare truncating (LoF)

1 in 2,200

34 rare PASS variants

Rare synonymous (reference)

1 in 230

142 rare PASS variants

Truncating variants are far rarer here than missense — that gap, in human units, is what constraint means for FOXO3B. 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 120	1 in 2,100
South Asian	~43k	1 in 98	1 in 7,700
Remaining (unassigned)	~30k	1 in 84	≈ 1 in 15,000
European (Finnish)	~27k	1 in 420	1 in 2,400
Admixed American	~22k	1 in 160	1 in 1,500
African / African American	~21k	1 in 150	1 in 1,300
East Asian	~20k	1 in 120	1 in 580
Ashkenazi Jewish	~13k	1 in 370	none seen
Middle Eastern	~2,884	1 in 100	none seen

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 3 coding exons well covered in gnomAD exomes; exon 2 poorly covered; exon 4 marginal. Genomes: 1 of 3 (exons 2, 4 below).? see exons ↓