We specifically presented evidence for a ciliary mechanism in human EFHC2-associated renal failure, identified the V-ATPase subunit ATP6V1A in the etiology of mammalian osteopetrosis, and demonstrated a role for the Golgi protein GLG1 in trafficking IFT-A proteins into cilia as a molecular mechanism for short-rib thoracic dysplasia. This evidence concerns the gene EFHC2 and osteopetrosis.