New approach to analyze genetic and clinical data in bisphosphonate-induced osteonecrosis of the jaw

Oral Diseases (2012) 18, 580–585 Objectives: Osteonecrosis of the jaw (ONJ) is a major complication associated with long‐term use of bisphosphonates (BP). We aimed to investigate the effect of CYP2C8 rs1934951 SNP and its relationship to a number of clinical and biochemical factors in 46 Hungarian subjects with bisphosphonate‐induced ONJ. Methods: Blood samples were collected from each subject and genomic DNA was extracted. SNP analysis of CYP2C8 gene was carried out by predesigned TaqMan primer/probe sets. The genetic data together with clinical and biochemical variables were evaluated by chi‐square test, logistic regression, and principal component analysis (PCA). Results: The risk of mandibular localization of ONJ was 19.2‐fold higher in subjects with AG genotype than in normal GG genotype. PCA revealed strong positive correlations between maxillar localization of ONJ and a group of variables including intravenous BP application and serum lipid markers. Mandibular localization of ONJ was correlated positively with serum calcium, 25‐hydroxy‐vitamin D and PTH levels, oral BP application, and the length of BP therapy. The degree of the disease and the number of recurrences were correlated with the application of hormone‐deprivation therapy for breast cancer patients. Conclusion: The statistical approach applying PCA to our data may contribute to the better understanding of factors playing role in the development of bisphosphonate‐induced ONJ.