FOXO3 gene variants and human aging: coding variants may not be key players

Area of Science:

• Genetics
• Aging Research
• Molecular Biology

Background:

• The Forkhead box O3 (FOXO3) gene is a key factor in aging and longevity.
• Previous studies linked single nucleotide polymorphisms (SNPs) near FOXO3 to human longevity, but the functional variant remains unknown.
• Accurate identification of functional variants is crucial for understanding FOXO3's role in aging.

Purpose of the Study:

• To sequence the coding region of the FOXO3 gene in a long-lived Japanese American population.
• To identify the actual functional genetic variants associated with longevity.
• To refine resources for fine-mapping the FOXO3 gene region.

Main Methods:

• Sequencing of the FOXO3 coding region in a cohort of long-lived individuals.
• Bioinformatic analysis to identify and validate single nucleotide polymorphisms (SNPs).
• Comparison of identified variants with known databases and homologous sequences.

Main Results:

• Of 38 previously reported variants, 6 were misalignments with FOXO3B (ZNF286B), and 2 were solely attributable to ZNF286B.
• The remaining 30 published variants were unconfirmed and deemed too rare to be significantly involved in longevity.
• A novel, nonsynonymous coding variant (Gly566Ala; rs138174682) in exon 3 was identified, present in multiple ethnic groups but rare in the study population.

Conclusions:

• Many previously associated FOXO3 variants are likely artifacts due to pseudogene misalignments or are extremely rare.
• The identified novel variant (rs138174682) is unlikely to be a major determinant of longevity due to its low prevalence.
• Further research is needed to identify the true functional variants of FOXO3 associated with human longevity.