Dr. Aimée M. Dudley, PhD
Pacific Northwest Research Institute
Development of a Validated Functional Assay for Citrin Missense Variants
Accurate interpretation of genetic variants remains a major challenge in the diagnosis of citrin deficiency, particularly for missense variants, which are difficult to classify using DNA sequence information alone. Functional assays are valuable because they directly measure protein activity on a quantitative scale, enabling consistent comparison across variants and the definition of biologically meaningful ranges of protein activity. Model organism systems such as yeast preserve key aspects of human protein function, while offering advantages in scale, cost, and speed.
This project will establish a validated, scalable in vivo functional assay for citrin missense variants using a yeast-based system (Yarrowia lipolytica). By leveraging the ability of human citrin to functionally replace its yeast ortholog, the assay enables quantitative measurement of citrin activity through yeast growth. The study will generate high-quality functional data for a strategically selected panel of 81 clinically relevant variants, including known benign and pathogenic variants, high‑frequency disease‑causing alleles, and variants with prior biochemical characterization.
The resulting data will provide a robust framework for evidence‑based variant interpretation and improve the field’s understanding of how altered citrin function contributes to disease. By establishing and benchmarking this assay, the project will deliver a valuable clinical and research resource while laying the groundwork for future large‑scale functional studies that will further expand variant interpretation and deepen insight into citrin biology.
