Ethnic factors in Perthes disease: a retrospective study among white and Asian population living in the same environment.

The aim of this study was to find out about the incidence of Perthes disease in different ethnic groups living in similar environments. Among the child population of Bradford, between 1991-1997, we identified from the file notes twenty-five cases of Perthes disease among the white European population (with an incidence of 5:54500 for the year 1997) and one case of Perthes disease among Asians (with an incidence of 0:16100 for the year 1997). There were two positive family histories of Perthes disease and only a case of bilateral Perthes disease. There was no significant difference in the incidence of Perthes disease among the rural and urban population. We conclude that under similar environmental circumstances the genetic factor plays an important role in the predisposition to Perthes disease.