However, osteoblast differentiation and bone matrix deposition in vitro were normal, as in the case of Lrrk1 KO mice.102 Interestingly, a mutation of human Plekhm1 has been reported to cause osteopetrosis due to the defects in vesicular transport, later lysosomal, and ruffled border formation in mature osteoclasts.101 Full-leg radiograph from the affected patient showed cortical sclerosis of the pelvic bones and the inhomogeneous sclerosis at the metadiaphyses of the distal femora, tibiae and fibulae. Here, LRRK1 is linked to osteopetrosis.