PPP2R3B and muscular dystrophy: Two key findings in relation to the potential cellular mechanism of pathogenesis were: (1) the identification of prominent ppp2r3b gene expression in somites and axial muscle fibres in contrast to very limited expression within the vicinity of bone, and; (2) the identification of reduced vertebral bone density and altered intervertebral structure, as well as mitochondrial defects similar to those previously reported in muscular dystrophy models which followed normal muscle formation and occurred in the absence of muscle fibre (Z-disc) defects10.