TRAPPC2L is a core subunit of the TRAPP (trafficking protein particle) complexes, multisubunit tethering factors conserved across eukaryotes 1. The protein functions as a stable mammalian TRAPP component involved in early-stage endoplasmic reticulum-to-Golgi vesicle transport 1. TRAPPC2L interacts with other TRAPP subunits, including TRAPPC6a, where it acts as a putative adaptor for complex assembly and membrane trafficking 2. Functionally, TRAPPC2L regulates intracellular vesicle trafficking and autophagy processes essential for cellular secretion 3. Pathogenic variants in TRAPPC2L cause a rare autosomal recessive disorder characterized by early-onset progressive encephalopathy with episodic rhabdomyolysis 4. The disease presents as severe neurodevelopmental disorder with variable muscle involvement, classified among congenital muscular dystrophies 4. Clinical features include developmental delay, seizures, postnatal microcephaly, and hyperCKaemia 4. Pathogenic missense and protein-truncating variants disrupt TRAPPC2L protein function, impair TRAPP complex assembly, and cause membrane trafficking delays with Golgi morphology alterations 25. Additionally, TRAPPC2L dysregulation has been identified as a transcriptional driver of metastatic heterogeneity in prostate cancer progression 6.