Although it is currently not known whether POPDC2 and POPDC3 also bind PDE4, mutation of leucine 155 to histidine in POPDC3, which corresponds to leucine 173 in POPDC1, was recently identified in a patient suffering from limb-girdle muscular dystrophy (LGMDR26, OMIM 605824). Here, POPDC2 is linked to limb-girdle muscular dystrophy.