PNKD (PNKD metallo-beta-lactamase domain containing) is a probable thioesterase that likely plays a role in cellular detoxification processes, acting on unknown alpha-hydroxythioester substrates 1. While the protein can catalyze hydrolysis of S-D-lactoyl-glutathione to form glutathione and D-lactic acid in vitro, this reaction occurs at very low rates and is not physiologically relevant in vivo 1. The primary clinical significance of PNKD lies in its association with paroxysmal non-kinesigenic dyskinesia (PNKD), a movement disorder characterized by spontaneous attacks of abnormal involuntary movements without loss of consciousness 23. PNKD is caused by mutations in the MR-1 gene (now known as PNKD) and represents one of the three main forms of paroxysmal dyskinesias 34. The condition typically has a benign course and may not require treatment with advancing age 5. Additionally, genetic variations at the PNKD locus on chromosome 2 have been associated with colorectal cancer risk, with the susceptibility SNP showing strong linkage disequilibrium with inflammatory bowel disease risk variants, suggesting pleiotropic effects 6.