MYH13 encodes a superfast myosin heavy chain specialized for high-velocity, low-tension muscle contractions 1. Expressed primarily in extraocular, laryngeal, and syringeal muscles, MYH13 mediates rapid movements against minimal load through a unique biochemical property: its actin-bound form has much weaker ADP affinity than conventional fast myosins (MYH1, MYH2), enabling rapid myosin-actin detachment and fast shortening velocity 12. Located at the 3' end of the mammalian fast/developmental myosin gene cluster on chromosome 17, MYH13 is evolutionarily ancient but exhibits regulatory independence from adjacent genes, controlled by a super-enhancer 12. Beyond muscle physiology, MYH13 variants associate with neurological and psychiatric conditions: genome-wide association studies identify MYH13 polymorphisms as risk factors for formal thought disorder in schizophrenia 3 and idiopathic normal pressure hydrocephalus (iNPH), where mutations impair ependymal and choroid plexus function 45. MYH13 is also upregulated during C2C12 myoblast differentiation 6 and overexpressed in ovarian cancer bowel metastases 7. These findings suggest MYH13 has pleiotropic roles extending beyond specialized muscle physiology to developmental and neurological processes.