Natural variation in a glucuronosyltransferase modulates propionate sensitivity in a C. elegans propionic acidemia...

Area of Science:

• Genetics
• Metabolic disorders
• Model organisms

Background:

• Inborn errors of human metabolism result from mutations in metabolic genes, leading to rare diseases.
• Propionic acidemia is caused by impaired propionate catabolism, resulting in harmful accumulation.
• Genetic background influences disease penetrance and expressivity, but modifiers are hard to find in humans due to low statistical power.

Purpose of the Study:

• To identify genetic modifiers of propionate sensitivity using a Caenorhabditis elegans model.
• To investigate the role of natural genetic variation in modulating metabolic disease phenotypes.
• To establish a framework for using C. elegans to study genetic contributions to inborn errors of metabolism.

Main Methods:

• Genome-wide association (GWA) mapping in wild C. elegans strains.
• Phenotypic analysis of propionate sensitivity.
• Genetic analysis of modifier genes, including the glucuronosyltransferase GLCT-3.

Main Results:

• GWA mapping identified genomic regions associated with reduced propionate sensitivity.
• Natural variation in the C. elegans glucuronosyltransferase GLCT-3 (homolog of human B3GAT) influences propionate sensitivity.
• Loss-of-function mutations in glct-3 decreased propionate sensitivity in C. elegans.
• C. elegans exhibits an expanded glct gene family, suggesting gene family size impacts propionate sensitivity.

Conclusions:

• Genes not directly involved in propionate breakdown can modulate propionate sensitivity.
• Natural genetic variation plays a significant role in the manifestation of metabolic disorders.
• C. elegans serves as a powerful model for dissecting genetic modifiers of inborn errors of metabolism.