Differences in idiopathic inflammatory myopathy phenotypes and genotypes between Mesoamerican Mestizos and North American Caucasians: Ethnogeographic influences in the genetics and clinical expression of myositis

Center for Biologics Evaluation and Research, FDA, Bethesda, Maryland, USA.
Arthritis & Rheumatology (Impact Factor: 7.87). 07/2002; 46(7):1885-93. DOI: 10.1002/art.10358
Source: PubMed

ABSTRACT While the sampling in ethnicity and geography is limited and may reflect referral or other biases (13, 34, 35), other differences in the distributions of global IIM clinical and serologic groups are striking, as are the variations in genetic risk and protective factors in published populations around the world (Table 6). Although attempts were made in all these studies to minimize confounding and biases, by evaluating consecutive subjects who met identical criteria and using predefined standardized questionnaires and evaluations, possible variations in clinical or other assessments may have resulted in different ascertainment. For example, although there is epidemiologic and anecdotal evidence of differences in the frequency of IBM and CAM in different ethnogeographic populations (12, 23, 36), which suggests that such differences may be due to genetic or environmental heterogeneity among these populations, the paucity of IBM and CAM in Mesoamericans and in other populations compared with the US Caucasian IIM population may also be a result of referral bias or possibly a limitation in the diagnostic capabilities at certain centers. In addition, because patient populations studied at referral centers may not be representative of the total IIM populations from which they are drawn, extrapolation of these referral data to entire IIM patient populations may not be warranted. Overall, however, we do not believe that referral and assessment biases alone could account for the many significant differences seen among these populations.

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Available from: James D. Malley, Sep 11, 2014
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