Association between the CYP24A1 rs2762939 polymorphism and vascular calcification in Indonesian patients with chronic kidney disease on hemodialysis

Vitamin D plays a key role in mineral metabolism, and its dysregulation contributes to vascular calcification, a major complication of chronic kidney disease-mineral and bone disorder (CKD-MBD) in patients undergoing hemodialysis with CKD. The <i>CYP24A1</i> gene encodes 24-hydroxylase, the enzyme responsible for degrading active vitamin D metabolites and its polymorphisms, particularly rs2762939, have been linked to variability in vitamin D status and coronary artery calcification. The aim of this study was to assess the association between the rs2762939 polymorphism of <i>CYP24A1</i> and vascular calcification in Indonesian patients with CKD undergoing maintenance hemodialysis. A case-control study was conducted in 92 hemodialysis patients, including 46 with vascular calcification and 46 without. Genotyping of the rs2762939 polymorphism was carried out using PCR-RFLP, and the amplified products were separated by electrophoresis on 4% agarose gel. The frequency of vascular calcification was found to be significantly higher in patients with diabetes mellitus than in the control group (19 (82.6%) vs 4 (17.4%)), whereas in non-diabetic patients the frequency of vascular calcification was lower compared with controls (27 (39.1%) vs 42 (60.9%)). A statistically significant association between CKD etiology and vascular calcification was observed (<i>p</i>=0.001). The prevalence of vascular calcification was lower among carriers of the mutant C allele (45%) compared with the G allele (51.4%), although this difference was not statistically significant (OR=0.77; 95%CI: 0.38-1.56; <i>p</i>=0.592). The rs2762939 polymorphism of the <i>CYP24A1</i> gene was not significantly associated with vascular calcification in Indonesian patients with CKD undergoing maintenance hemodialysis. Further studies with larger, ethnically diverse cohorts and integration of vitamin D status are needed to clarify the genetic contribution of CYP24A1 and related pathways to vascular calcification.