الملخص
<p><b>OBJECTIVE</b>To investigate association of vitamin D receptor (VDR) gene polymorphisms with the susceptibility to chronic periodontitis (CP) of Han Nationality.</p><p><b>METHODS</b>Buccal swabs from 166 patients with severe, moderate and mild CP respectively and 80 matched control individuals were collected. DNA was extracted from these buccal swabs using Chelex-100 method. VDR BsmI, ApaI, TaqI were tested with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The distribution of the genotypes and allele frequencies in the patient and control groups were analyzed.</p><p><b>RESULTS</b>The frequency of VDR ApaI allele A was significantly higher among patients with CP than controls. Frequencies of VDR ApaI allele A were significantly higher in severe CP patients than in moderate CP and mild CP respectively. There was no significant difference in the genotype distribution or the allele frequencies of VDR BsmI and TaqI between the controls and CP patients.</p><p><b>CONCLUSIONS</b>These data indicate that VDR ApaI allele A may be related to the susceptibility to CP in Han Nationality.</p>