Paget's disease in patients of Asian descent in New Zealand.

Paget's disease is considered to be uncommon in Asian people, but we have noted a recent increase in the number of Asian patients referred to our clinic, on a background of an apparently decreasing prevalence in the population of European descent. In this article, we report clinical and epidemiological features of patients of Asian descent with Paget's disease, referred between 1973 and 2010 to the Auckland Paget's disease clinic. No Asian patients were referred before 1993, but 14 have presented between 1993 and 2010, with a median of 8 years between arrival into New Zealand and time of diagnosis. The patients were predominantly of south Asian origin. None of the 8 patients tested carried a mutation in exon 8 of the sequestosome 1 (SQSTM1) gene. The number of new Paget's disease referrals expressed as a proportion of the potentially at-risk Asian population in the Auckland region (derived from census data) was 1/10(4) in 2006 to 2011. Amongst Europeans, the corresponding value decreased from 10/10(4) in 1986 to 1991 to 2/10(4) in 2006 to 2010. The increased number of people of Asian descent diagnosed with Paget's disease in the Auckland region has paralleled the increasing size of the local Asian population. The continuing decline of Paget's disease in the European population, in conjunction with the emergence of the disease in the Asian population, supports the view that an environmental determinant to the disease exists and that Asians are not genetically protected. It also implies that the apparent reduction in Paget's disease prevalence in western cities is unlikely to be explicable by the rising Asian population of these cities.