In 2011, a mutation in the Dync1h1 cytoplasmic dynein heavy chain (DHC) gene was discovered to be the cause of CMT2 disease in four generations of an afflicted family and was designated Charcot Marie Tooth type 2 O disease (CMT2O)10. The gene discussed is DYNC1H1; the disease is Charcot-Marie-Tooth disease axonal type 2O.