DMP1 and autosomal recessive hypophosphatemic rickets: Therefore, we wanted to determine if the Dmp1 null mouse which closely mimics the human ARHR phenotype with abnormal dentinogenesis, chondrogeneisis, and mineralization (Ye et al., 2004, 2005; Ling et al., 2005; Feng et al., 2006) also has muscle weakness.