COL2A1 mutation as a cause of premature osteoarthritis in a 13-year-old child.

Diagnostic assessment of osteoarthritis in children and adolescents is difficult. Here, we report the sixth family with a COL2A1 mutation R275C. The index patient, her mother and her three brothers had severe coxarthrosis, in some cases requiring surgery. Only the mother was hard of hearing, and only her children had brachydactyly of the fourth digit. The index patient suffered a femoral neck fracture after minor trauma at a time when osteoarthritis was not yet radiologically detectable. Hip fracture or osteoarthritis of unclear origin in childhood should prompt genetic work-up for the purposes of correct classification and genetic counseling.