CHDH (choline dehydrogenase) is a mitochondrial transmembrane enzyme that catalyzes the oxidation of choline to betaine, serving as a key regulator of choline metabolism 1. The enzyme plays critical roles in cellular processes by producing betaine, which functions as both an important methyl donor and organic osmolyte 2. CHDH demonstrates tissue-specific and temporally regulated activity, as evidenced by its transient activation during mouse oocyte meiotic maturation, where it enables autonomous betaine synthesis essential for egg development 3. The enzyme is involved in mitochondrial autophagy following mitochondrial damage and is crucial for maintaining mitochondrial integrity 1. CHDH dysfunction has significant clinical implications, particularly in male fertility where deletion results in diminished sperm motility due to abnormal mitochondrial morphology and reduced ATP content 2. Genetic polymorphisms in CHDH are associated with various conditions including reduced sperm concentration, tooth agenesis risk, and bipolar disorder susceptibility 456. Additionally, CHDH expression is elevated in breast cancer tissues and promotes metastasis through IL17RB/CREB1 signaling activation, suggesting its potential as a diagnostic marker and therapeutic target in metabolic disorders and cancer progression 71.