α-Actinin-3 deficiency is associated with reduced bone mass in human and mouse

► α-Actinin-3 is expressed in osteoblast cells while its closely related isoform α-actinin-2 is not. ► Loss of α-actinin-3 in mice results in reduction of bone mass. ► α-actinin-3 deficient osteoprogenitor cells showed altered expression of genes involved in bone regulation. ► α-Actinin-3 deficiency is associated with lower bone mineral density in older women.