Mitochondrial proteins and congenital birth defect risk: a mendelian randomization study

Area of Science:

• Genetics
• Developmental Biology
• Biochemistry

Background:

• Mitochondrial dysfunction is a suspected contributor to congenital birth defects.
• Observational studies are limited by bias and confounding factors.
• Mendelian randomization (MR) offers a robust method to investigate causal relationships using genetic variants.

Purpose of the Study:

• To investigate the causal effect of mitochondrial protein levels on the risk of common congenital defects.
• To examine specific defects including orofacial clefts, congenital heart defects, ear, urinary, nervous system, and limb malformations.

Main Methods:

• Utilized summary statistics from the FinnGen consortium for various congenital defects and controls.
• Extracted genetic variant data for 66 mitochondrial proteins from the Human Plasma Proteome Atlas.
• Employed inverse-variance weighted (IVW) method as primary analysis, with MR-Egger, weighted median, and MR-PRESSO for sensitivity analyses.

Main Results:

• Identified significant associations between several mitochondrial proteins and congenital defects.
• Found inverse relationships between specific mitochondrial proteins (e.g., pyruvate dehydrogenase kinase isozyme 1) and congenital heart malformation risk.
• Observed associations for mitochondrial proteins with orofacial clefts, urinary, nervous system, ear, and limb malformations.

Conclusions:

• Provides genetic evidence supporting a causal role for mitochondrial protein levels in congenital heart, urinary, ear, and limb malformations.
• Suggests mitochondrial dysfunction may contribute to the pathogenesis of structural birth defects.
• Highlights the need for further research to confirm findings and explore underlying mechanisms for potential translational applications.