The Screening Of Periodontitis' Susceptible Genes

ObjectiveThe studies reported here were to detect the genetic polymorphism of five susceptible genes in periodontitis patients and healthy controls. We compared the different frequencies of five sorts of alleles in periodontitis patients and healthy controls to know which single allele or multi-alleles would affect the development of periodontitis.It will provide beneficial references for the research in etiology of periodontitis from genetics.MethodCase groups were consisted of 106 patients with moderate,severe periodontitis and 33 patients with aggressive periodontitis.80 subjects of age and gender matched with healthy periodontal conditions were enrolled.Clinical parameters were measured and recorded by a single examiner,which included probing depth(PD),clinical attachment loss(CAL),sulcus bleeding index(SBI)and tooth movement(TM).Genomic DNA from leukomonocyte was extracted with saturant sodium chloride,amplified with HLA-DRB1*1501 primers then digested with Hphâ… restriction endonuclease. Genomic DNA from peripheral venous blood was extracted with saturant sodium chloride,TNF-A-308,IL-1B⁺³⁹⁵³,VDR,ER amplified with specific primers then digested with restriction endonuclease.The polymorphism in above genetypes was examined after electrophoresis on polyacrylamide gel and ethidium dromide staining.The differences between the periodontitis patients and healthy controls were analysed by Z-score test,the differences in clinical index among groups which taken different number susceptible alleles were performed by mean square analysis. Results1. The frequencies of HLA-DRB1*1501 allele were 0.47 in chronic periodontitis patients, which in healthy controls were 0.26, and highly statistically significant difference was detected between the chronic periodontitis and healthy controls by Z-score test. The frequencies of HLA-DRB1*1501 allele were 0.47 in aggressive patients, which were 0.21 in healthy controls. There was a significant difference between them.2.The frequencies of TNF-A-308 alleleâ…¡were 0.45 and 0.53 in chronic periodontitis patients and aggressive periodontitis patients, however the frequencies of TNF-A-308 alleleâ…¡were 0.19 and 0.32 in their respective healthy controls. There was a significant difference between periodontitis patients and healthy controls.The frequencies of IL-1B⁺³⁹⁵³ alleleâ…¡were 0.26 and 0.38 in chronic periodontitis patients and aggressive periodontitis patients,which were 0.10 and 0.09 in their respective healthy controls.There was a significant difference between peridontitis patients and healthy controls.3. The frequencies of vitamin D receptor allele B,vitamin D receptor allele A and vitamin D receptor allele T were 0.51,0.33,0.43, 0.31,0.35,0.42 were in healthy controls. There was a significant difference between chronic periodontitis patients and healthy controls for vitamin D receptor allele B. The frequencies of vitamin D receptor allele B, vitamin D receptor allele A and vitamin D receptor allele T were 0.53,0.62,0.56 in aggressive periodontitis patients, and the frequencies of alleles in healthy controls were 0.24,0.30,0.59. Highly statistically significant difference was detected between the chronic periodontitis patients and healthy controls for vitamin D receptor allele B and receptor allele A.The frequencies of estrogen receptor allele X were 0.53 and 0.48 in chronic periodontitis patients and aggressive periodontitis patients, which were 0.34 and 0.23 in respective healthy controls.The difference between periodontitis patients(including chronic periodontitis patients and aggressive periodontitis patients) and healthy controls were significant. We did not detect any difference between periodontitis patients and healthy controls for estrogen receptor allele P.4. 51 persons(48.11%) took more than three susceptible alleles, and 7 persons(6.60%) did not take them.However in healthy controls, the number of the persons who took more than three susceptible alleles was 5, and 38 persons did not take any susceptible alleles. Further subdividing Z-score test showed that a significant difference existed between periodontitis patients and healthy controls. In aggressive periodontitis patients, 17(51.52%) persons took more than three susceptible alleles, 3(9.09%) persons did not take any susceptible alleles. Highly statistically significant difference was detected between the aggressive periodontitis patients and the healthy controls.5. For the persons who took more than three susceptible alleles, the probing depth, clinical attachment loss,sulcus bleeding index and tooth movement were 4.29±1.02mm, 4.67±1.29mm, 3.67±1.35 and 0.93±0.47. The above clinical indexs in persons who took less than two alleles and did not take susceptible allele were 3.14±0.93mm, 3.24±1.10mm, 2.65±0.92,0.43±0.41 and 3.10±0.83,3.22±1.00, 2.67±0.68,0.21±0.29 respectively. There was a significant difference in periodontal probing depth, clinical attachment loss and tooth movement among the three groups; and so those were in aggressive periodontitis patients and healthy controls.Conclusions1. The frequencies of homozygous for HLA-DRB1*1501 allele, TNF-A-308 alleleâ…¡, IL-1B⁺³⁹⁵³ alleleâ…¡, Vitamin D receptor allele B and estrogen receptor allele X in periodontitis patients were higher than that in healthy controls. Except for that, the frequencies of Vitamin D receptor allele A in aggressive periodontitis patients were higher than that in healthy controls. It suggested that the above alleles were periodontitis' susceptible alleles.2. Multi-susceptible alleles would easier lead to periodontal disease.3. The cooperation of multi-susceptible alleles was a risk factor for the development of periodontal disease.