A single-base mutation resulting in an arginine-519-cysteine (R519C) mutation of type II procollagen (COL2A1) has been shown to result in precocious osteoarthritis with mild spinal chondrodysplasia without severe foreshortening (OMIM 604864). The nature of childhood disease among affected individuals has not been described. The recent presentation of four children with this mutation allows us to provide clinical correlation. This form of premature osteoarthritis may present in childhood and should be considered in the differential diagnosis of childhood arthropathy presenting in the context of a positive family history. Copyright 2001 Academic Press.