Lack of support for the presence of an osteoarthritis susceptibility locus on chromosome 6p

OBJECTIVE: To replicate, in a Northern Irish population, the previously reported association between a locus on chromosome 6 and hip osteoarthritis (OA). METHODS: Patients with hip OA were identified from a registry of patients who had undergone total hip replacement surgery over an 8-year period at a single large orthopedic unit in Northern Ireland. Patients identified as index cases were contacted by mail and asked to reply only if another family member also had undergone total hip replacement surgery. Using this approach, we identified 288 sibling pairs concordant for primary hip OA. DNA was extracted from peripheral blood, and microsatellite markers were amplified by polymerase chain reaction and subsequently genotyped. RESULTS: No evidence of linkage to this region was demonstrated by either 2-point analysis or multipoint analysis of 17 microsatellites. CONCLUSION: The reported association between a locus on chromosome 6 and hip OA could not be confirmed in this population. Different methods of ascertainment and phenotyping of OA may contribute to the current inability to replicate genetic associations for hip OA.