The Study Of Association Between Endemic Fluorosis And Chemical Elements And Ameloblastin Gene Polymorphisms

Objective: To understand the distribution of chemical elements in soil.To investigate the differences between patients and normal that come fromdifferent state of the illness after preventive measurement implemented ofsome chemical elements and fluoride levels in urine, To observe thedistribution of ameloblastin（AMBN） gene polymorphism in coal-firedpolluting fluorosis in Chongqing province and investigate the relationshipbetween AMBN gene polymorphism and the susceptibility to dentalfluorosis. To further illustrate pathogenesis theoretical foundation.Methods:（1）use the ecology of comparative study to analysis ratesand chemical elements levels.（2）Using case-control study, to take patients who have fluorotic teethand fluorosis skeletal and controls fluorin ion selective electrodedetermination urine fluorine content.（3） Using case-control study, to enroll100children aged8-12and30adults with dental fluorosis in Wushan and Fengjie counties of Chongqingfrom December2010to February2011as case groups,100children aged 8-12and30adults with non-dental fluorosis were enrolled as internalcontrol groups, and50children and30adults with no-dental fluorosis awere selected as external control groups in non-epidemic area in Yubeidistrict. DNA was extracted from peripheral blood sample of these people.Genotype of AMBN gene7extron538₅40delGGA,10extron657A>Gand13extron986C>T loci were detected using polymerase chainreaction-restriction fragment length polymorphism （PCR-RFLP）.Results:（1）In Wushan the soil nickel（r=0.553P=0.050）, iodine（r=0.571P=0.041）, and prevalence rates had weaker positive relationship,the level of fluoride and iodine were higher than background value, was1.84,2.89times of background value, respectively, PH value of92%counties was higher than background value present alkalinity, prevalencerate of Jianping county was64%, and the level of cadmium was11.41times of background value. the relative relationship was not found betweenthe level of chemical elements of Fengjie county and prevalence rate.（2）In Wushan county children case and internal control group is morethan external control group in copper, zinc, calcium, magnesium, iron andurine fluorine content; the adult patients’ magnesium, iron and urinefluoride are more than internal control group, magnesium and urinefluorine are high than two controls. In Fengjie county children’s copper,iron are lower than external control, calcium and urinary fluorine are higher.case group’s copper, calcium and magnesium is higher than internal control group, Fengjie is higher than Wushan in zinc, calcium, magnesium andurine fluorine of children case groups.（3）7extron538₅40delGGA loci among case, internal and externalcontrol groups’ difference was statistically significant （X²=14.353P<0.05）.The difference among case, internal and external group of657A>G had notstatistical significance（X²=2.972P>0.05）. The difference among threegroups of986C>T loci had not statistical significance （X²=4.319P>0.05）.To compared with two control groups, the frequency of GGA/GGA decent（X²were8.957、3.405，respectively, P<0.05）, the frequency of-/-increased（X²were5.134、6.833, respectively, P<0.05）. Univariate analysis showedthat individuals carrying-/-genotype had increased risk of sufferingfluorosis （OR were2.7,5.9, respectively, P<0.05）. Compared with internalcontrol group, CT genotype of case group increased （X²=4.139P<0.05）, inepidemic-area individuals carrying CT genotype had increased risk ofsuffering fluorosis（OR=2.1P<0.05）.Conclusion:（1） The alkaline and high fluorosis soil may increasehuman fluorine intake; nickel, cadmium, iodine content in soil is related tofluorosis.（2） Elements of resist to florin are deficient in endemic area. Further toexpand to research other chemical elements，environment and heredity.（3）7extron538₅40delGGA and13extron986C>T locipolymorphism in AMBN gene maybe one of the susceptibility factors of coal-fired fluorosis.